Brass plug is soft and wont corrode, bolt will never seal. Use a female hex head, wont round off like a square plug head. Pipe tape /dope whatever you use to aid in removal. Plugs should be mandatory on auto trans pans, messy job without them!
Pop rivets work well.
Shave the head off and knock the rest into the pan for draining, then pop a new one in and a little RTV on the inside over the end for assurance of no leaks and slap her back on.
It takes a little longer to drain obviously, but it's a lot easier than adding a drain plug that wont leak.
