IMO I would just grab em with a pliers and break that chunk of plastic off with it and turn it in as dirty brass. Should only take seconds rather than 10x that trying to get all the plastic off for only a 2x better price.

This is definitely a case of "how far do you want to take it" haha =P I don't think either way is very time efficient, but sometimes I do find myself sitting there spending 10 minutes trying to get a tiny piece of brass free from the tube its connected to... sometimes you just have to win the battle no matter how long it take haha