i've used Powerburst once - from recommendations on here. The carpet looked fantastic and it was a real minger to start with. I gave a prevac, prespray, mechanical agitate, acid rinse and a groom. It was polyprop and customer was over the moon as so was i - i'd found a new wonder cleaner.A week later - the customer phoned to say some of the marks had wicked back - i went to see and the carpet didnt look good at all to the point where i was wondereing if it was me that had cleaned it!!! I was really disappointed - i'd never had a problem like that before.I recleaned it with bonnet and Fusion Clean and fixed it - carpet all ok 4 weeks down the line.Was my first experience with Prochem Powerburst and my last - i'll stick to detergo free!!! I've used Spitfire and similar in the past and never had problems - but Powerburst makes me wonder how it leaves the carpet. May have just been a one off but from the above topic maybe not..............