I've had excellent results with absolutely no problems cleaning carpets
by just using a liquid  laundry soap and using the large size front
loading commercial washing machines at the local laundromat.  The
tumbling action and hot water do the job, and I haven't had any problems
with tearing or damage of any kind.

This also works great for the cover on the mattress cushions from the
Westy.

I've washed seatcovers too, but there's a problem with the paper insert
that fits to the metal seat bottoms on the lower part of the front seats
and holds the lower edge in place. The paper strip comes apart in the
washing process.  I'd recommend doing these by hand  The backrests don't
have this problem and that works fine.

The quality of the upholstery and carpet material is really quite good,
with the exception of the brown corduroy stuff, and it cleans up
beautifully. There are some 'scotchguard' like products around that help
keep things looking good longer.

Chuck Hill