After trying different chemicals to clear a drain, with no long lasting effect, I stumbled across this online. I actually bought mine direct from karcher. Anyway, after connecting it to my karcher 2.25 sprayer, I fed about 1 metre into the drain where it met an obstruction. I switched on the machine and, I was presented with lumps of white fat. I manually fed the hose into the drain, gradually using the whole 7.5 metres. I could not believe how much fat and debris there was to be found! I then withdrew it and repeated the process two more times and was left with a perfectly free running drain. The whole process took me about 15 minutes. I have to recommend this product.