Nassarius snail take care of the detritus and poo of your fish and aerate the LS
Nerite snail are great cleaners for your glass, rock & LS sometimes.
Astrea snails same as above but for sure they will clean the LS
those are the ones i recommend, like and own... there are other kind of snails that do the same but be rather bigger than the mentioned ones.
but blue leg hermits are better for leftovers.