Living in a truck

Dr. Bronners Peppermint soap works great. I use it at home to shower/ shampoo. It did well on the road when I traveled on a tour bus with my band. We had a shower on the bus, but you can use it to freshen up with a towel and some soapy water in the sink or bowl. You can find it at Health Food Stores and many grocery/ drug stores. Also, there is this foam stuff you can use on your hair like shampoo with no water. It's in a can like muuse...moose....muose, oh whatever.... but you put it in your hair, comb it through if you want, then towel dry. No water. I forgot the name, but I'll post it later.
You've just gotta keep yourself clean on the road. Not only for your health and appearance, but it also effects your morale and attitude. I feel good after a shower, but even if you just clean up and freshen up a bit, change underwear and socks, your attitude and frame of mind is better. This is proven even in survival situations or with soldiers in combat.