Arma Reforger
15 Achievements
Steam
Combat Hygiene
Flushed a toilet in-game. Details for this achievement will be revealed once unlocked
5.3%
How to unlock the Combat Hygiene achievement in Arma Reforger - Definitive Guide
The way I found this was by joining the Training mission/scenario, and going into the building immediately on the left, found a bath/restroom and flushed a toilet. Easy as that!