Just make sure
Its the conditioner and not the soap.
The conditioner is what coats the sides of the plastic and makes it "slippery" so stuff don't stick and slides right off. 3 gallons of water is perfect (10% of your tank capacity or more), but cold water and ice is the ticket.
The first time you use it I "highly recommend" two bags of ice cubes (or chips), a cup of laundry soap (liquid works here) and a 30 minute drive before you dump. The ice knocks the stuck on crud off the tank walls.
The water should run BLACK if you have a clear elbow on.
That is the "stuck on" composted stuff leaving your tank.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW