this may not be new news, but thought it might help someone...
this was on a sportbike, but should apply universally.
PO of bike stripped oil pan drain plug threads and had installed a helicoil (or similar) insert that finally failed.
removed pan (alum) and took to a bike friendly machine shop. they proposed several solutions, but the one they recommended was the least complicated (and cheapest).
they drilled just enough to completely remove the thread, and then tapped the hole with NPT threads to accomodate a standard "plug". as you know, NPT is tapered, so the plug installs to a very tight seal. i used about 2 turns of teflon tape at the bottom portion on the plug for further piece of mind. this type of NPT plug is available at any corner hardware store as well.
of course this plug does not have a magnet, but the guys at the shop said they would make one if i couldnt live without it.
shop cost was $40 including the plug.
cost of a new pan would have been approx $150
i did NOT want another "insert" of any type installed in the pan, and thought this was a very good and cost effective solution.
i hope it may help someone else later. - benton