CLAY BAR ALTERNATIVE Safely and easily removes rail dust, water spots, tar, bugs, and paint over spray from automotive paint and glass surfaces BETTER THEN CLAY Poli-FLEX Rubberized CLAYBLOCK® and LUBER® Cleans, purifies and soothes surfaces & Paint in Seconds. CLAYBLOCK® is awesome. CLAYBLOCK®-a single block can clean a full size vehicle 15-25 times, making it quite possibly the most economical paint cleaner system available on the market today.