Mouthwashing Gun Case Code: Protection Kit Guide

The Mouthwashing gun case code is 739. It opens the Protection Kit in the medical room. On the regular story route, visit the cockpit, open the locker and use the Code Scanner on its barcode to discover the number. For the Taking Notes Steam achievement, use the same code at the relevant objective without returning to the cockpit.

Those are two routes to the same case, with different achievement consequences. If you only need the solution, remember medical Protection Kit → 739. The instructions below stay focused on the puzzle until the marked story-spoiler section.

01

Open the Protection Kit: quick solution

When the current objective brings you to the gun case:

1. Find the Protection Kit in the medical room.
2. Interact with the case's code entry and enter 739.
3. Open the case and collect its contents as the scene directs.
4. Continue the objective rather than looking for another gun-case number.

This route is documented by both the English achievement guide and the Chinese complete walkthrough linked below. It does not require a promotional code, a website account or a developer-console command. The number belongs to an object inside the story.

If you want to solve the clue within the scene, follow the cockpit route in the next section. If you want Taking Notes, read its section first: returning for the clue conflicts with that achievement's stated condition.

02

Where the cockpit clue is located

The community walkthrough directs you to the cockpit locker during the sequence it labels Chapter 19, six hours before judgment. Open the locker and use the Code Scanner on the barcode there. The saved research identifies it at the back of the locker; the resulting code is 739. Return to the medical room and use that number on the Protection Kit.

Treat the scene description as an orientation aid. Mouthwashing jumps between different points in time, so a familiar room does not mean you are in the same objective as your previous visit. The current task and the scene's title card are more useful than trying every remembered code whenever you enter the medical room.

For help locating your place in the presentation order, use the Mouthwashing walkthrough. It connects the puzzle to the surrounding objectives without treating the game's sequence as a straightforward chronological journey.

03

Taking Notes: skip the return trip

The current official Steam achievement list defines Taking Notes around opening the Protection Kit without returning to the cockpit. That condition matters more than simply knowing the code. You can open the correct container after finding its clue normally and still have taken the wrong route for this particular achievement.

For the community-documented achievement route, go to the medical room at the relevant objective and enter 739 directly, instead of making the cockpit detour. Both cited player guides describe this approach. The English guide places it in Chapter 19, while the Chinese guide pairs that chapter with the six-hours-before-judgment title card.

Keep these distinctions in mind:

• Regular progression: inspect the cockpit clue, then open the kit.
• Taking Notes attempt: open the kit without returning for that clue.
• Achievement evidence: Steam supplies the condition; player guides supply the route and number.

This guide has not independently tested the unlock. If you already returned to the cockpit during that attempt, do not assume entering 739 afterward restores eligibility. The available condition does not establish a way to undo that visit. Consult the achievement guide before deciding whether to revisit the sequence.

04

Do not confuse the three lock codes

Mouthwashing uses several numbers in different scenes. They are not interchangeable, even though searching for “the code” can bring them up together.

Cheater concerns opening Cargo before acquiring the Code Scanner. Taking Notes concerns opening the Protection Kit without returning to the cockpit. One is about when you obtain a tool; the other is about avoiding a particular return trip. Using the Cargo number on the medical case will not satisfy either task.

The cake puzzle guide covers another use of scanned information: nutrition ingredients and the birthday cake. Its dispenser numbers are separate again. Keep the object name beside a number if you are taking your own notes.

05

If the number does not seem to help

First, check the container. The solution on this page applies to the medical-room Protection Kit, not the Cargo door or the axe case. Matching the object prevents an unnecessary search for alternate combinations.

Second, check your current objective and scene. The walkthrough documents the kit-opening sequence later in the presentation order. If the game is directing you elsewhere, follow that task or compare your scene with the walkthrough instead of assuming every visit to the room offers the same interaction.

Third, distinguish opening the case from earning Taking Notes. If the container opened but the achievement did not appear, changing the number is not the next step: 739 already performed its puzzle function. Review whether you returned to the cockpit. The sources do not establish randomized combinations, a platform-specific replacement code or a guaranteed method for repairing a missed unlock mid-scene.

06

Story spoilers: what the gun does not change

Story spoilers begin here. Stop reading if you only wanted the case solution.

The gun appears in the game's later violence, including Jimmy's confrontation with Swansea. The community walkthrough documents that sequence, but opening the Protection Kit is not evidence of a branching rescue route. The reviewed sources do not establish a different story ending unlocked by obtaining the weapon more efficiently or by earning Taking Notes.

For the larger sequence and the difference between observed events and interpretation, read the ending explained. This puzzle guide avoids expanding those events into unsupported choices or alternate outcomes.

07

Source and testing boundary

The number, clue route and scene placement come from published Steam Community walkthroughs. The achievement condition comes from Steam's current official listing, reviewed on October 24, 2026. These sources support the distinction between normal progression and the achievement attempt; they do not establish that this site's editors completed either route themselves.