Isn't it better to use a sponge to clean the inside of the aquarium glass versus the expensive magnetic ones out in the market? The reason being because the magnetic ones just release back the crud back into the tank vs, if using a sponge, wiping the it along the glass, then bring it up and rinse in bucket of RODI water and dip it back into the tank and continue to rinse of the crud makes more sense - no?