Gloves, hooking up and turning on the tank flush hose and main sewer hose, dumping the black tank until nothing more is visible through clear plastic fitting, shutting that valve and opening the two gray tank valves, letting all that drain out, and putting everything away takes no more than 15 minutes, even with a 35 gal black tank and two 30 gal gray tanks. I think that most campers drain in roughly the same time, because the bigger the tanks, the larger the drain pipes, up to a point, from my observation. Takes me about the same time whether dumping at the campsite, or at the dump station. Just get your procedure down pat, do it, and don't worry about the guy behind you. Most campers are very patient at the dump site, especially if they can see you are not diddling around, and are proceeding at a reasonable pace. JMHO
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.