Nothing will eat waste. Only way to remove it is with a gravel vac. If your waste is accumulating that fast, you are almost certainly overstocked. What kind of fish and how many do you have and in what size tank?
I've never seen anything eat waste but I guess it's possible. I wouldn't count on buying something and hoping it will eat it. Your tank is pretty much fully stocked, probably a little overstocked, so you don't really have room for more fish anyway. Cut down on how much you are feeding them. Also, how often are you doing water changes? With the stocking level you have, you should definitely be doing a water change once a week.
i have a spot on stocked tank and i find waste builds up reasonably quick but as someone said already bn plecs make a lot of waste and i have three in there. every second day i get a piece of airline tube and go around picking up all the waste. its annoying and tedious but it keeps it clean...just how i like it