i also work in the trade and remove locking wheel bolts on a regular basis, i find the easiest method is to get a large hammer and an extension bar and hit the whhel nut direcly 7-8 times first to shock the threads, i have then got the left hand taper removers and usually find that i have no problem. a collegue actually timed me removing a full set of 4 from a ford and i did it in just under two minutes