I have a whirlpool tub in the house and cleaning it is not easy. Does anyone have any idea about the cleanliness of one of these? Very, very clean, until it shines?

Yes, buy the pills that are used in a dishwasher collision of a small number of them and fill with hot water, Ea, for the bath tub. This really helps all the dirt thats holes relax in the jacuzzi. Try using a minimum number of chemicals. Simple brush baking soda and vinegar can work. Just elbow grease.