My idea is to put Fresh Step Kitty Litter in your ashtrays and don't forget the car ashtray.
An unscented version with low dust would be good.
I would love to see biodegradable kitty litter. We use quite a bit of litter in our household, with four kittens/cats. We have (for the moment two litter boxes) and feel like we load our trash can with mostly litter. We believe in recycling and being an earth friendly family. We've tried the “environment friendly” litters, but they fall short on the needs of our animals, and leave our home smelling of waste.
Our family has adopted four kittens in the past six months, two are brothers, and the other two are rescue animals. We care about the environment as much as we care about animals.

sprinkle Fresh Step on auto fluid leaks to soak them up
When changing FreshStep Kitty Litter, I lay a little of the old kitty litter on top of the clean so that my cats know that this is their kitty litter. One time when I just gave them fresh, they freaked a little and pottied in the house. Since I have been putting a little of their familiar scent, no accidents!