Stick with a traditional clay bar, whether Meguiar's, Mother's, etc. The TW Liquid thing is a joke...it takes a very simple, straightforward process and complicates the heck out of it and doesn't even return as good a finish when you're done.

A friend of mine who owns a detail shop here in SoCal. Wrote a great review on his website. This guy is one of maybe 3 people I know who I would trust with my cars (if I didn't know how to do all this myself)! Hopefully you haven't opened the package and you still have your receipt.