Keep the powerheads running--particulates fall out of moving water faster than they do standing water. The small grains are acutally very valuable--they provide better media for the bacteria than the larger grain sizes (surface area: volume). This is true in SW as well--I don't rinse sand for my salt tanks, I just take precautions to prevent it from being agitated (ie, don't aim a powerhead at it), and let it settle on it's own.
When I put play sand in my 55 gallon I did not rinse it at all. I place a plate on the sand in the tank and poured in the water in very carefully. I did not have a cloud at all! It was clear as a bell...
Well, if you're not adding ammonia then the beneficial bacteria will having nothing to feed on and just end up dying. See, it takes ammonia in the tank to get a fishless cycle going. You may want to drop into the Freshwater Newbie forum and read the Sticky thread titled Cycle to get the whole process and also the instructions for a fishless cycle.