Believe it or not, I didn't realize it until I read the question on one of those 'trivia question a day calendars, the answer is loofah: the 'sponge' we use in the shower or bathtub.
Well, No,Knowledge, you washed out on the winning prize....(Did I mention that there was a prize?). For the correct answer the prize was loofahs for life plus $100 to keep you in Pears Soap in order to scub-a-dub-dub in the tub:)..................G'night.