Hi, CharleyWhiskey. I was the one who originally asked all of these questions. We've enjoyed camping with our Scamp a few times now, and I think I've got the hang of things. The first time we camped, I was stressing over the idea of emptying both tanks, but it turned out to be a lot easier than I expected. I am now the "poop pro" of our family of four and find emptying the tanks to be a breeze.
A few things...
Since our Scamp was used, I bought a new hose. (Just wanted my own instead of handling someone else's icky one.) I went with the Rhino that was already mentioned, and it works great, but I'm not sure I would choose it the second time around. The stiff flex hose can be a bit difficult to handle, and it does NOT fit in my 1990 Scamp 16' mounted tube, though we're pretty sure we can replace that with a bit larger one. (However, I can't see the end nozzle on a Rhino ever fitting into a tube. You would have to remove it from the hose each time, and then you would need to store it separately.) Right now, I keep the hose in a plastic bin that slides under the Scamp at the campsite until I need to use it.
I usually don't empty until it is time to depart from our campsite, though once I had to empty halfway through our stay. I do as others mentioned: I empty the gray tank first, and then empty the black. After emptying the black, while still hooked up to that tank, I do flush a fair amount of water through the hose before moving it to the gray tank. (I get Husband to flush and hold down the toilet mechanism while I am outside.) I do the same with the gray. (Again, get Hubs to run a bunch of water through the sink to "clean" the hose.) The entire process probably takes less than 10 minutes. Very easy!
Around our area, the full hookups are only a few bucks more, and it is WELL WORTH IT to not have to repack and hookup the Scamp and tow it to a dump station mid-camp. Just in case you didn't catch that, it is WELL WORTH IT.
It is a lot of work to hook up the Scamp (and then to bring it back, unhook, and re-level) to the tow vehicle, yet it takes about 10 minutes to empty both tanks. IMO, it's not worth the stress of moving it.
We are a family of four, and we can usually go a weekend before we need to dump, but we mainly use the campsite's bathhouse. The Scamp tanks are small - makes sense, the Scamp is small - so if we only used the Scamp's facilities, we could probably fill up the tanks within 1-2 days. We try to reserve the Scamp bathroom for middle-of-the-night use. I do wash our small amount of dishes in the Scamp, and we brush our teeth there. That's about it.
If we were to camp somewhere for longer than a weekend, I would probably go ahead and hook up the gray tank to the sewage and let it flow directly so I wouldn't have to deal with checking it. And then just move the hose to the black when we needed to empty that.
So far, we have found camping in the Scamp to be surprisingly simple and an utter joy! Our family just got back last night from a trip in her, and as soon as we put the kids to bed, Husband and I were already researching campsites for our next trip!
Best wishes to you in your Scamping adventures!