Have you considered using "Swheat Scoop" litter? It's a wheat base - as the name implies - and the granules are fine, and I've been using it for years now. And it's flushable.
I have had no problems with our cats, over the years, trying to use it as a food supplement. There is no odour to it either. And Pet Valu carries it, and because we have a 6 cat household, - 1 is a foster cat - we purchase the Multi Cat bag, and it generally does us a month.
Initial start up is expensive, but I find it cheaper in the long run. Just recently we had a multi cat household friend - she has 8 kitties - switch to the Swheat Scoop and swears by it. In fact, she wishes she had switched a year ago when we first suggested it to her.