Reverend Red Bull
I've been using a generic Harbor Freight O-ring for my trans plug for 5 or 6 yearly drain/fill cycles now instead of the crush washer. (Didn't like how the crush washer looked first time I drained it. Didn't want to use it the way it looked, but also didn't want to wait for a new one to show up in the mail, so grabbed the O-ring assortment off the shelf.) I just throw a new one on with every drain/fill, and it's never leaked a drop.