Only if it only removes ammo from the weapon currently being held. I think that's what you tried to say but I couldn't understand.
Good god, you can't be serious about considering it! This is too overpowered. I've gone a long time not noticing if I dropped my ammo in my gun, this will just be another thing to look for 24/7.
Besides, if someone else is holstered and you use it while they are looking at them the player will just outright kill them. When a player is holstered it's usualy seen as a sign of "I'm not going to be an immediate threat" but this changes that.
What it needs is to have some charge up (such as standing still for 3 seconds) and have a minor visible effect on the player who is using it.