I have been the sewer cleaning business fr about 15 years. I dont claim to know it all, but it is extreamly rare for me to find situation that I have not seen before. I can't begin to to count the times I have had to save the weekend warrior who though; "Any idiot can clean a drain." In just the two messages I have read there are many errors. I could write page after page of procedure how to clean a drain. Think of it this way, after one rents the machine, spends his or her time, (usally a whole day) cleaning the drain, (usally making a mess of the job area, and the cloths being worn)and returns the machine. How much money do you really save? Even worse a person does all the above and dosent clear the line, a plumber still needs to be call. Bottom line leave the drain cleaning to the professional!