Cleaning the interior covers

I've seen some folks mention they have cleaned the interior seat / mattress covers. What did you use. I was thinking of Woolite in a bath tub and hanging to dry. Did anyone have trouble with shrinking? Did you put them in the washing machine?

I know that I won't put them in the dryer but wonder about the machine ?

[MariaG]

I used the upholstery attachment on my carpet cleaner. I did it first with a little laundry detergent, then with plain water to rinse. I picked a nice sunny dry day and let them air dry outside on the kids trampoline. I've taken cushion covers off my couch before and washed them in the washer, then put them back on damp and let them dry, but it's a pain wrestling them off and on. I thought the carpet cleaner was easier.

Washing machine when we bought it used and the water was filthy.