if u get a good finish using a sponge then use one..if u don't then don't...personaly never seen the need as your makin more work for yourself...it just livens the set back up and u do what u do anyway after that as u would without one (wet t, dry t)....i tryed it once yonks back and it left a grainy finish, but then i've seen guys usin em and gettin a really nice finish, so whatever u do thats your way of doin it so never mind what anyone else thinks...