Just a suggestion Use the bucket but put a hose connection into the bottom on the side of the bucket then hook up your 5/8 hose as the bucket fills the weight of the water should cause the water to empty. I had a 2000 Pop-up and at times the water wouldn't drain correctly sometimes I would use my hand as a plunger to force the water out the drain once it started it would be ok also try to have your drain hose as straight as possible out the side of the camper.
2004 Jay Feather 25E
2001 Ford Expedition 4X4 EB 5.4 3.55 rear
2004 Ford Expedition 4X4 EB 5.4 3.73 rear