I had this same problem about a month ago and I went to my local reps, they told me about mojave. I bought the spray mix rather than the granule, it is specifically used for parking lots and driveways. The one problem you are going to have is leaching but if like you said nothing is a round I'm sure that it wouldn't be a problem. It has a minimum residual of 6 months. I also thought it would be a great service to sell at large stores and malls.