I've tried coating them with everything... vaseline, fingernail polish, even varnish.
None of it worked.
Bingo! In fact most of the reputable sites such as the Lyme Disease foundation and others only recc. phsically removing the beast. They are now saying that even if there are parts of the tick left in after removal that it should not pose any problems. I did a lot of research on this a few months ago when we had a major tick episode and found a ridiculous amount of home methods that don't work. Stick with just pulling the buggers out.