I use wood pellets and it has all but eliminated the urine smell! The poop smell doesn't get covered, but the only time it smells is in the morning, right before I clean it, I could probably eliminate any odor by removing the stool twice a day. It doesn't bother me though, so it works really well for us.
I had a tracking problem which is why I switched, there was litter everywhere, even in my bed! The wood pellets are only $3 for a 40lb bag and that lasts us 3-4 weeks which is a TON cheaper than what I was paying for litter, and we used to get the cheapest litter $7/ bag. So the wood pellets I can get 2 months worth for what I was paying for one month with the clay litter, it's a no brainer for me!