This is a video explaining how I plan to shower or dip shower in the back of a mini-van on my USA road trip in 2012.
This video below is explaining my proposed shower system for my USA road trip in a mini-van in 2012.
The following based on my travel experiences.
The buckets are available new for $5 at Lowes. Used can be found for free. You would be much better equipped with a water container than a bucket. OR, 5 one gallon containers (milk or water) available free on recycle day.
The cargo van is a good idea. I much prefer a small full size van over a mini van. Get a van with "barn doors". Open the doors and add a tarp and you have a shower room.
One challenge will be choosing parking spot for the night. Walmart or other big box stores parking lots are popular. Be careful parking in residential neighborhoods. I have come close to being towed.
A toilet in your van is a very bad idea. A laundry soap container with a few ounces of Listerine works for well for number one. McDonalds for number 2. You are never very far from a McDonalds or the like in usa.
Bathing in your van is another bad idea. I don't think it will take you very one to figure that one out.
12v electric to heat water is another bad idea. Ambient temp will usually be warm enough for a shower.
A single or double propane burner is best for cooking or heating water, if you must.
Best to spend some time choosing where you want travel. Huge sections of usa are BORRRRRRRRRRING. I am talking about the people and sights. The worst are the medium density strip mall areas. More interesting are the desolate and urban areas.