Dumb Plumbing Error

I tried to remove a washer seat from the shower hot water by using this boomerang looking tool. Unfortunately, I stripped it because I didn't have it seated properly. So, now we go through washers in about 3 months, since it is in such bad shape.

Am I out of luck? Is there any other way to remove it? It is an older house, and there is no access to the plumbing from behind. The plumbing is buried in tile on a mud lath. Received on Sat Feb 16 2002 - 08:11:25 CST