[DebNJim B]

We have been in one location since Oct, w/FHU. We dump the black tank once a week and the grey tanks twice. It's just DW and I and we use lots of water (hold pedal down for 5 full seconds each flush) We use Walmart TP, tests show it breaks down better than RV paper. I am currently using Digest it based on reviews on this forum, but I don't see any better performance than using one capful of Calgon with one capful of Dawn or laundry soap. I generally run the flush through several cycles of around 5-10 gals per cycle and then just let it run about 10 gals with the valve open.
This has been our practice for the last 8 years of snow birding. We have tried many different additives, but none seem to work better than the Calgon/soap eco treatment. After 25 yrs experience in liquid waste business I can tell you that there is nothing that will break down waste in less than a week.
As for poo-pyramids, always leave all valves closed till dumping and use plenty of water and lots of flushing. I know that's hard when toting but it's important.