He will find a way to drink, wallet or no wallet. However, if I gave him the wallet and then he died of alcohol poisoning, I would feel guilty. Therefore, if it was me, I would keep the wallet.
However, it sounds like he could use some emergency medical help.
Try very hard not to get sucked into the drama and emotions around this. (easy for me to say...) Dealing with a alcoholic who is hitting bottom is horrible. What help do you have in place for you?
Love and blessing to you and him
Robin