thread locking compound isn't something I'd put my life on, it wouldn't pass in technical inspection on the track, so it's not as safe as lockwire or the tabbed shim, if you're going to lockwire it, there are proper methods to be followed which will keep things safe, the gauge depends on the application, if it's a 10mm stud, you'd probably want something like .030 stainless, make sure not to mar the wire too, (if you got those pliers from HF) they have done that to me so I had to do some work with a file on them, really nice ones you'd be working on F4's with are probably nicer