Search: loufa; loofa; loofah
Why: I am editing an article about making your own spa, and the girl spelled loofah like "loufa." I think it comes out of the sea.
Answer: Well first, it's actually luffa. And second, get ready to have your mind blown: it's a plant that grows on a vine! WHAT! Cultivated in India and the Middle East, the fruit is a cucurbit, related to gourds, melons and cucumbers. You can also eat it, and you may have seen it on a menu listed as Chinese okra. Well, I never.
When mature, the fruit becomes a "tough mass of cellulose fibers." Use it whole or cut it up or put it in soap or put it on a stick or use it to wash your dishes. Anything goes!
Source: WiseGeek, Wikipedia, Luffa.info
The More You Know: When we first moved to Boston, Amy told me and Klepdog that she was glad neither of us filled up the bathtub with girly shit like loofahs and shower gel. The truth is that now I have a poufy sponge thing and some pomegranate body wash with moisturizing microbeads. I use it to scrub.