I do not know what everyone else's bathing habits are, but I shower everyday and use a loofah to help lather my soap and remove the dirt and grime from the day. I find loofahs to be better at retaining soap then regular washcloths. They also glide easier than washcloths allowing for easier scrubbing of needed areas like elbows, knees and bottoms of my feet.
Now I know it says to replace your loofah every three weeks, but mine usually last about three months. When they become unravelled, and fall apart is when I know I need a new one. Sometimes it's sooner then expected, and I always use a new one after any open sores.
I highly recommend for all your exfoliating needs.