I never put anything on my carpets.
My late mother used to sprinkle moth crystals, (not balls) on the floors and later vacuum them up. I'd never do that now with a cat in the house.
I've put those scented cork pellets on the floor, though. They are 3safe for bothe the floor and the cleaner.
Baking soda is great for cooking, keeping the refrigerator fresh, brushing your teeth, and polishing stainless steel.
Carpet Fresh, Love My Carpet, etc is awful, as are any scented beads, in or out of water. THat is only MY opinion. None of that stuff goes on my carpets. THey are Chinese...some are Karastan..100% wool.