I have a sandsifter, a sleeper goby. Nothing is on my sand. I have never seen fish droppings of any sort, ever.
I have had fish all my life. I have never had to clean fish poo.
Goldfish make the water dirty (rats with fins) thats as close to a nasty fish I ever had.
But in a saltwater, or a tropical freshwater tank fish poo has never been an issue, I never noticed poo unless it was coming out of the fish at that moment.
Do you really have poo problems, that you have to clean??? What kind of fish are you keeping???