I have been using Fresh Step multi-cat clumping litter NO SCENT.
I use 50 lbs of litter per month. People will come in my house the first time and ask if I still have my cat. After I say "yes" they ask what kind of litter I use. I tell them and they always say that they have never been in a house before, including their house, that has absolutely no smell and what do I do. I tell them nothing, there just isn't a lingering odor. I have one cat.
I have two litter boxes, one rarely used and the other used daily. I clean the litter box both morning and evening. I only totally change the litter box once a month. I put approximately 3-4 inches of litter in each box. However, if the second litter box has only been used once or twice a week, I will add some clean litter and exchange it with the other litter box.
I do, however, not only take the clump out, I also take the surrounding litter out as well. Therefore, I usually have to add additional litter during the month to keep it at the total of 3-4 inches.
I am now having difficulty finding the Fresh Step multi-cat clumping litter with NO SCENT in 42 lb packaging. Using the 25 lb box of litter is more costly, therefore, unfortunately I may have to try other less costly clumping NO SCENT litter and hopefully I will be able to find one that he likes as well.
If my cat does not like the litter, he will not use the box (but no accidents) and he paces until I IMMEDIATELY go to the store and replace the litter with what he is used to.