When doing mulch jobs, I use treflan 5g as my pre-emergent weed control. Today was a terrible day for a mulch job, but, hey, you've got to do something to make money right? Anyway, The job was an 8 yard mulch job on a $600,000.00 thousand plus house. It was about 93 degrees and muggy as hell. For some reason, the treflan that was on the sidewalk decided to break down quick and stain the sidewalk in front of their house. I'm guessing the humidity had something to do with this. Of course, it's not a normal sidewalk, it's those little pebbles, and they had it sealed about 3 weeks ago. Now, I need to know how to clean the yellow off of the sidewalk. I told the customer that water should do the trick. I forgot it's oil based. Hopefully dawn might work. I need some ideas tonight folks. I'm going back in the morning to take care of the problem......... Help!