Okay, here's what I've done to mine, but I don't actually know what the fabric content is on mine. I looked at the site and they don't seem to have mine there any more (I have two Bayside sofas: a blue/white floral and a green/white stripe). I have not washed the whole cover, but I have washed the seat cushions a few times. We have a bulldog who sneaks up on the sofa and drools her disgusting drool on the seat. The cushion covers washed really well. Just put them in the machine and washed them on cold, and let them air dry and put them back on when they were about 95% dry.

Bulldog #2 has a nasty habit of rubbing her face along the bottoms of our sofas after she eats, which creates a lovely brown (dog-food colored) stain along the front of the sofas. For that, I recently got a can of spray-on upholstery cleaner and scrubbed the heck out of the front of the slipcover while it was still on the sofa. Worked great.

Thanks! Had to smile at your bulldog stories.