When on an extremely budgeted road trip here in the U.S., you can still do a partial bath everyday since there are many clean public bathrooms for free anywhere in the U.S. (Unlike in so many other countries where you always have to pay to use a bathroom as it's big business!:)

A partial bath consists of washing your hair & face on the bathroom's sink, washing your under arms (very important!), brushing your teeth (also very important), wiping your body & private parts vigorously & repeatedly with a wet washcloth.

But inspite of not gettting a full shower for several days, a road trip of the U.S is still totally worth it especially upon visiting the beautiful U.S. National Parks whereby Washington state & Montana houses some of the best! (I'll publish several of them after Oregon.)

*After 8 days of no shower, it felt great to finally have one, later in the trip up in Washington state.