I used STPP for the very first time lastnight. I was happy with the results, although they weren't as drastic as I thought. I guess it takes a few washes to get the full effect. But I am happy with it! There were more suds than usual, although in a couple of loads that were full to capacity there were none, I figured it was because there was more clothes sloshing around than water. I didn't over load the machine, just filled it. I saw that the wash water was dirtier than usual, which was cool. The rinse water had like a few bubbles of suds if any and the water was clear. When they were done, my clothes didn't have a hint of detergent smell at all. Just smelled like water I guess you could say. My whites came out a bit brighter, my socks were definitely cleaner than usual. And a few shirts that were pretty dirty from helping a friend clean a shed came out spotless and clean smelling without any pretreating. I was quite happy with the results and can't wait til the next wash day to use it again. I washed everything in top loading direct drive Whirlpools and my towels in a front loading Huebsh at the laundromat. Used hot water and Arm & Hammer powder that contains Oxy Clean booster. One thing I noticed that Mixfinder also pointed out, was the towels and the jeans especially, felt a bit rough. I figured this was probably because the STPP must have stripped everything of past detergent and softener residue. Which is fine with me, that just tells me everything is getting cleaner. But I'm gonna have to use liquid softener once in a while seeing as how just dryer sheets didn't soften them up that much.