I actually have to do this on occasion due to sediment in the river here in Fort Myers. What I did was make a flushing cap using one of the faceplates for my March AC water pumps, and connect it to the generator room freshwater spigot. I will run freshwater thru the AC's for anywhere from 15 minutes to an hour, depending on water volume coming from overboard discharge. Here's my setup. I also have a similar hookup to go onto thru-hull fittings to reverses-flush the raw water intakes.20210721_102826.jpg