I have an washer/dryer all-in-one unit that I used in my house. I never used the dryer portion of the unit as it never completely dried the clothes; I opted instead to use a separate spin dryer which removes 95% of the water left in the clothes, and then threw them into a regular dryer to finish drying. My clothes would be completely dry in 20 minutes in the dryer.
I am still doing the demo on my short bus, but intend to use a mini washer/spin dryer (similar to the old Hoover washers with spin dryer), along with a compact 110v dryer (if I can fit it in), to do the clothes. So, I will not need any special or traditional washer/dryer hook ups.
Laundry will be a little more labor intensive, but it is no big deal to me.
Here is a link to the little washer/spin dryer that I have and a link to the compact dryer that I have: