I put about 1/2 c Borax, 1/2c Super washing soda in a utility tub with warm water and soak the bottles for about 15-20 mins, works way better than the cleansers they sell, and its alot cheaper! You can buy 4# boxes of those cleansers in the laundry soap isle at the supermarket for about $3. No scraping, even gets the pesky aluminum foil labels off the modelo bottles.