Sand or earth. This option does not absorb odors. This is the so-called "primitive" option for a cat, which it is accustomed to at the level of instincts.
Newspapers and paper. Put newspaper through a shredder – your pet will love it.
Sawdust. An excellent option for absorbing odors. The thickness of the sawdust should not exceed 10 cm.
Fuel pellets. An alternative to sawdust, they will also absorb odors quite well.
We have previously written about the reasons why a cat has stopped using the litter box.