Let's share some tips of things that people don't commonly think can be done.
I discovered that you can take the covers off of upholstered cushions, wash them in the machine in cold water and hang to dry. I have done it successfully (MANY times) with a nylon upholstery fabric with rubberized backing, as well as a cotton blend. The first time I did this was out of desperation, but after that it was routine.
I learned the hard way NOT to dry clean upholstery fabric with rubberized backing--it shredded. If someone tells you this can't be done...they're right! I totally ruined a two-year-old sofa when we were first married.
I recently washed some cushions where the cover couldn't be removed, and it worked fine. I put them in the bathtub, let them soak in cool water, squeezed out the water, rinsed them and squeezed out the water again. I used Simple Green so that it wouldn't suds as much as, say, Tide. They take about 3 days to dry--I put mine on a slatted lawn chair in the shade. I probably would not do this on something that would be expensive to replace if it didn't work, but I've done it to 3 rocking chairs so far where the alternative was to discard the cushions. It has worked fine every time. The fabrics have been nylon, microfiber and one with an unknown fiber content. Don't try to wash any fabric that has acetate in it.