you could also try a pressure washer after the cat litter..

tolbiny wrote:
I have a stone paver driveway that is not sealed as it is fairly new. A
guest's car had an oil leak on the driveway. I have tried the oil remover
that is safe to the environment and not supposed to harm the grass but it
doesn't work that well and I still have a darker discoloration on the stone.
Can anyone advise me about a procedure or product that has worked for them?
Thanks.