I had some of the powder that a friend gave me. It seemed the help the smell. But the kind I used had a strong scent that I didn't care for. It was alright. I usually use regular baking soda mixed with the litter.
Arm and Hammer makes baking soda, so I would guess that it would have baking soda as a basis.
If there are smells added then your cats won't like it, as they have sensitive noses and my insensitive nose finds most of them too strong so imagine putting that stuff in an enclosed space like a litter box. No thanks! In which case just skip over the added expense and sprinkle some baking soda (or whatever instructions are provided with that product) over your litter. It should improve the smell (baking soda does absorb odours) although not get rid of it completely.
I do find that a thick amount of solidly clumping litter is the best way of having no serious smells. If the pee clumps up really well in the stuff then the difference is huge and much improved.
It's just baking soda with some additives. Just buy regular, cheap baking soda to help keep the odors and moisture in the litter box down. I do it with every change and it helps immensely.