Because I was dumb enough to strip the threads on my oil-pan/crankcase plug, my intent is not to tighten the replacement anywhere near as much as has been my habit.
On the other hand, the possibility of the plug vibrating loose and depositing a gallon of oil on somebody's street now becomes a concern. _I was just about to drill a hole across the hex part of the plug to safety-wire it so the darned thing won't unscrew itself, but don't want to accidentally degauss the magnetic feature by drilling. _Is that a realistic possibility or should I just drill, baby, drill?
Just wrap the wire around the hex head and attach it to whatever you're going to attach it to.
Drill it. I've done a few to prep motorcycles for track use. Didn't hurt the magnets in the drain plugs.
There is no way you could effect the magnets by drilling.
Have you considered replacing the plug with a plug repair kit like Snyder's sells? T-3080-RK If your car is a show car, this won't be your fix; but if the car isn't judged, not many people are going to look at your pan to see if you've got the correct plug.
When I was young and strong I used to strip the threads on oil pans because I was afraid they would back out unless they were socked down tight. I finally got smart and cut the open end wrench in half. Now I can put all the pressure I want without getting enough leverage to strip the plug out. I feet good because I could crank on the shortened wrench giving it all I had and I never lost a plug or stripped one out after I made that adjustment. Unfortunately, now that I am no longer young or strong I need to go back to a longer wrench!
The cork in a bottle of wine should work. After you drink it you get a new plug and won't care if it falls out and perhaps you'll keep pulling the cork out so you can get another bottle for another replacement plug and of course you loose that plug and ...well I think you see where I'm going with this.