When we say 100% Guaranteed to work..we really mean it. Dear Sir, Thank you for your prompt action on my refund. Even though the Main Line Cleaner didn’t work for me,I won’t hesitate to try your products again. You stood by your product and stood by your word ! This is refreshing in this day and time of rip off ads. I appreciate the refund but I would rather have had the drain go down.Thank you again, Carl B.