I have fresh water quiet flush toilets which work
well, though there is still a long term buildup of scale that requires occasional vinegar treatment. Also don't turn off your pressurized water system when you leave the boat. The solenoid valves require positive pressure to stay sealed and the pressure provided by gravity is not enough. Until we understood what was happening I replaced two valves because we would return to the boat and find the toilet
bowls full and the water tanks
empty and several cycle on the bilge
pumps (it did keep the bilges fresh though). Once I found that water pressure was required to maintain the seal and left the fresh water pump
on when we left the boat we had no more problems. Twelve years later I still have a spare valve and 2 rebuilding kits.