The Sonus Ultra-Fine Clay is meant to be a maintenance clay that you can use frequently. If your paint has heavy contamination, you may want to use a medium grade clay to do a deep cleaning. The standard
Clay Magic clay bar does not have that much more cut than the Sonus.
If you want to try a really kick-butt clay, try Gliptone:
http://www.autopia.org/auto-parts-ac...em_Step_1.html
This is a clay product that is no longer being made in the States, but I can assure you it performs.