If you need to wash on the go, the other options are terrible: you'd need to store your nasty duds and wait for the sweet salvation of a washing machine at your destination. Or you could stop intermittently at quarter-sucking laundromats. Neither is a great option.
Here's a description of the genesis of the technique, courtesy of Steinbeck himself:
Quite early on my trip, however, I invented a method for washing clothes which you will go a long way to better. It came about this way. I had a large plastic garbage bucket with cover and bail. Since the normal movement of the truck tipped it over, I tethered it by a length of strong elastic rope of cotton-covered rubber to the clothes pole in my little closet, where it could juggle to its heart's content without spilling. After a day of this, I opened it to dispose of the stuff at a roadside garbage can and found the most thoroughly mixed and kneaded garbage I have ever seen. I suppose all great inventions spring from some such experience. The next morning, I washed the plastic bucket, put in two shirts, underwear, and socks, added hot water and detergent, and hung it by its rubber rope to the clothes pole, where it jiggled and danced crazily all day. That night I rinsed the clothes in a stream, and you've never seen clothes so clean. Inside Rocinante I strung a nylon line close to the window and hung the clothes to dry. From that time on, my clothing was washed on one day of driving and dried on the next.
That is a long way of saying, "Put the clothes in a bucket with some water and some soap." Read on for an even longer version with photographic accompaniment.
Step 1: Equipment
- dirty clothing
- a lidded five gallon bucket
- some detergent
- enough room in your backseat or trunk for the bucket
You will need these for drying:
- functional rear windows
(There are so many uses for a telescoping pole, five gallon bucket, and a painter's drop cloth. I've kept them in my trunk on the off chance that I'd need emergency seating, an emergency tent pole, or just needed to paint myself out of an emergency. They've saved a few trips to the mountains and a trip to the beach. I have yet to find myself in a painting emergency, but it's all about the peace of mind. Be prepared.)
Step 2: Put everything into the bucket
A note on detergent: this is a tiny amount of space and a tiny amount of clothing. Do NOT put in too much detergent. I used a quarter of the recommended amount of laundry detergent, and it was too much. Just remember that any soap you add will be soap you'll need to rinse out. Save yourself some consternation and err on the side of too little.
Step 3: Close the bucket and drive
Secure it into the back seat or the trunk.
Then drive a few hundred miles. (Or roughly double that amount if you're in a civilised nation that has its act together and uses metric.)
Step 4: Rinse
Dump your sudsy water someplace safe. Like on a lawn or anyplace with enough topsoil to filter out the tiny amount of soap you used. Unless your clothing is covered in human feces (a legitimate concern depending on where you stopped for a meal and your personal hygiene), you should be safe dumping your gray water almost anywhere. If you're covered in filth, you should hold onto your doo-doo water. Somebody might want to roll around in that grass where you dumped it, and they probably don't want to unwittingly roll around in your poop. (Or your child's poop.)
Fill the bucket about a quarter of the way, then rinse and wring your clothes. Dump the water and repeat.
Step 5: Wring and hang dry
Then re-wear or fold and store.