Go easy on the chems in an empty tank. My experience is that they are hard on the valve seals. If you use a full dose of chems put 5ish gal of water in the tank.
That point of reference comes from the tried and true practice of scrubbing the tank after dumping (dump tank, close valve, add full dose of chems, 5gal water and a bag of ice and drive to your next destination. Empty tank or eave it in until next time. The ice /water will scrub the sides and many report restore accurate sensors.
2016 3500 6.7L DRW
2010 Starcraft 329BHU TT