yes mate they widely used, and the most widely used method of removing them is to lock 2 nuts together as mentioned and undo using bottom nut, will only work if you tighten the nuts up tight.....something your not doing if theyre spinning together.

If you use a normal pair of nuts (not the ARP nuts) then they wont damage the thread at all no matter how hard you tighten them...as they'll strip well before damaging the head studs.

Get some muscle into it and they'll come off

Cheers
Dan