Well I'm glad you asked Mike! The problem of course is that due to the filter bolt's location it's hard to get an impact driver on it to belt with a hammer, although I've had some success with a pneumatic rattle gun after I've bashed the next size down socket over the remains of the bolt head, and I've probably had more success just lopping the head off with an angle grinder, being careful not to damage the canister.
Years ago I bought several NOS chopper chrome oil filter bolts with 1" head bolts, (none of those poofy 17mm head bolts that you see everywhere now) and of course unless you're a fcuking moron and you stood on the 3 foot breaker bar to tighten it up because you forgot to replace the big O ring and your canister is leaking oil still, you'll never have a problem.
Having said that, I'm pretty sure Honda used the 12mm head so people couldn't overtighten the bolt, and rip out the thread from the lower crankcase, because we all know that some folks shouldn't be allowed to touch tools...........