It would be hard to do with the sloshing around while traveling, the alarm will be going off. Sure, grey water tanks usually don't have much left after draining, but your black water tank should have around 5 gallons put back in after draining.
Richard & Jill
2014 Flagstaff 832IKBS Classic Super Lite
2018 Silverado 1500 Crew Cab Z71 4WD All Star Edition
Camping since 1989
Car Shredder Op/Tech, Scrap Metal Recycling - retired
I deserve hazard pay when camping with my relatives.