Formula 90 powder is the best selling carpet cleaning product in the world. Probably our best seller as well. It is a well buffered cleaning detergent, most people put it in the tank of their portable or stock container of their truckmount. When I was cleaning this and One Clean were used almost exclusively. One scoop per 10 - 15 litres of water or one scoop per litre for truckmount stock solution. If the carpet is not too bad, one thats cleaned regularly, then cleaning with the wand without a pre-spray will give very good results. Should it require a pre-spray then you can spray from the wand or use a seperate sprayer. Again I always achieved excellent results. This is mainly due to the Biosolv it contains which is a powerful citrus degreaser. Very rarely leaves any marks which require further spotting. Never personally had any issues using heat even through the truckmount, in fact Paul King who has a beast of a machine which has a seperate Propane burner uses this and hes has red hot water coming out thewand most of the time.