yes, they work really well. We use them in our spas in the stores, and they pick up all sorts of stuff that gets in the water just from people's hands. The scum Balls work just like the scumbugs and are half the price. The only thing you must watch out for, is sometimes customers forget to take them out when changing/cleaning their filters and they accidentally get sucked down into the plumbing (mainly on older spas).
Happy new year Mendo!
