I played around with this idea for a few minutes, but it looks like this type of thing outright kills monsters which isn't what I'm going for. I want to take them down to a sliver of life and punch them to kill them so I get experience as well as the drops.
I might try something like this in conjunction with a dark room for harvesting gun powder from creepers though.
I might try something like this in conjunction with a dark room for harvesting gun powder from creepers though.