We recently cleaned an upscale movie theater. The head maintenance guy required us to do a rotary cleaning of the entire common area. We used a low speed rx-20 to clean everything and it looked great. Couple days later he calls back and says that spots have returned all over the area. I went back and encapsulated the area with a pad and pulled out a substantial amount of soil from the spots. He calls back saying that the spots are still there and we have to get them out. We went back and encapsulated the spots again. My friend got this job through his company, I do all his cleaning for him (he doesn't want to give it up yet), and will not bill the guy or pay out on the job until the maintenance guy is completely 100% satisfied with the job. How else would you guys try and clean these spots? They are large spots, possibly a large soda but not sure.