Unfortunately it doesn't send all the SMTP stuff that "really" gets your name off a list. As I understand it, if there's a human on the receiveing end of your bounce-back, they might take your name off the list. But if it's automated, Mailwasher doesn't send the appropriate message to make that happen. I'm still looking for something that does, that will work for personal use. Seems like the "good ones" are designed for businesses and run into hundreds of dollars to buy.
I do like Mailwasher to clean things up though, and preview what messages you have, so you don't have too much wierd spam on your computer itself.