I love ADA products, but this is one that I didn't really feel like I got my moneys worth on. I found that sticking the diffuser to the side of the sink, filling it up with bleach & letting it drain through works best. After the bleach drains out, fill it up with water, add some dechlorinator & let it drain through again. Another trick that'll keep your diffuser cleaner a little longer is to squirt some Excel right on the disk when you do a W/C.