[ukcol]

I assume you could most easily open an AF117 up with a pipe cutter.

If you are going to the trouble of opening one up why not clean out the gunk and the tin whiskers? Then you could refill the case with something that the tin whiskers could not penetrate. Silicon sealer may be suitable, reassembling the transistor before the sealer goes off?

I don't know what chemicals are in the filler in these transistors, so be careful as it may be toxic.