The
loofah melon (also spelled
luffa, by the way) has two main uses in
Taiwan.
The "sponge" consisting of the tough dried veins of the overripe gourd are used mainly for scrubbing pots and pans. Taiwanese has a special word for the various brushes used on pots: chhe3. The most common chhe3 is made out of a segment of bamboo finely split into dozens of splints at one end and unsplit at the other. I did not see loofah used as a bath brush until it was introduced as such from the West in the late 1980's, even though Taiwanese do a brisk business in bath brushes of various sorts. My wife's grandfather used to scrub himself quite viciously in the shower, prompting comments from the family on how much he loved cleanliness.
Loofah is also eaten as a vegetable, either stir-fried or in soup. Since its flavor is mild and its texture soft and melon-like, it does well to be stir-fried with small dried fish or salted black beans or other salty, chewy things. Naturally one does not use an overripe loofah for eating, because of how tough the veins become. But the young melon is tender and something like a large cucumber. The Taiwanese name for the loofah, chhai3-koe1, translates as "food-melon".
In my wife's dialect, the loofah "sponge" has a different name: chhai3-koe1-poo5 "food-melon 'cloth'". I think the name "cloth" is meant to suggest that the loofah sponge is quite a bit softer than the bamboo chhe3. Interestingly, one of my Taiwanese dictionaries gives the English name of the loofah gourd as "dishcloth gourd".