Going off of a strictly statistical point of view, there isn't that many situations where you would actually want to aim at yourself. Even if there's a 70% chance there's a blank in the chamber, you might as well just shoot someone else since it's a 1/4 chance the next live bullet will hit you. I suggest for the multiplayer game mode, after attempting to shoot another player and failing, you are forced to shoot yourself once. (With or without a chance to use items, I'm not sure)
This would increase the stakes that comes with shooting another player, and increasing the viability of shooting yourself.