I've seen people using acid rounds of grenade launcher to hurt themselves, why is this for? I still don't get it

its used to lower da in the run da is a thing in modern re games where if you get hurt more then your da is lower making enemies a lot calmer and easier to predict and some bosses easier to kill, the acid rounds are used in times you have to wait anyway so you can avoid losing time to getting attacked by enemies on purpose

Oooh now things are clearer, thanks a lot for the explanation dude! I appreciate it!