As for rinsing the bucket method is really the only way. You could try straining it (still have to rinse it) but I am not sure how long that will take and you may still get rising particles... Personally I use the bucket method... just put a 5g in the bathtub and let it overflow for a bit... then I empty all the water and start over... keep going until the water is pretty clear. Not flushing the sand is a big mistake if you buy certain play sands because they can be very silty and it is almost impossible to filter out later. Thick foam surrounds the tank.