Yup, I do the same thing.......for grey water.
One suggestion...Buy a used Pop-Up camper to try out for a few months or a year. The used Palominos are really inexpensive and you can see if you like it before you spend $10K and then have to sell it for 40 to 50% loss.
I bought a used Palomino 1200 Bronco for $1500 in great shape with everything working. I now realize that an inside shower is a must have for my type of camping. I use it to attend target shooting events and they park us cheek to jowl so taking a shower outside is right in the next campers face......even with a shower curtain and a bathing suit it is uncomfortable.
I also don't like not having a vehicle easily available once the camper is all set up.
I think I might go with a Toy Hauler next year....A small 18 footer wouldn't be much bother (I tow a 30' motorcycle trailer for my motorcycle club regularly)
Pull in, unhook, set up...done!