Bought this based on the reviews and I gotta say it 100% works. I had my invisalign retainers for 10 years and was placing them in a cup of water with mouth wash. Over time the retainers got gunked up and started turning my retainers with a brown tint that couldnt be removed even with brushing. I was thinking about replacing my retainers until I came across this product and gave it a shot. At first, the first tablet did clean it some and removed a lot of the brown tinting from my retainers. But after a couple of my uses, my retainers are crystal clear again. It removed 10 years of filth in a couple of treatments. I highly recommend this product if you want to keep your retainers clean.