Some cp'ers over here have used certain brand kitty litters as well.... and some are reported to be equal to APS. But after doing some research on the subject I found this may be unpredicatble (speaking for this side of the pond)
Our Kitty Litter and Oil Dri products basically come from one of 3 quarries in the USA. The quarry of origin has a major influence on if the product can be used or not. Some of the products are slightly alkaline and have poor physical and chemical stability. In addition, deodorants and harmful additives may be used.
Since these products are not labeled for horticultural use, they are not worried about suitability and consistancy. You can grab two identical bags off the shelf and one may be ok and one not.
Much less using the same product purchased from two different regions of the country.
Color is some indication of base mineral used, but not always.
In the states, heat enhanced clay based Oil Dri would probably be safer then our kitty litter...