Can you get the covers off the cushions at all and stick them in the wash? We have a steamer but we’re able to get all of the covers off plus remove all the curtains, mattress covers and net curtains when I bought it. I ended up dumping the original mattresses and got new memory foam ones made and just use mattress protectors from Ikea as the old mattress covers would not be able to fit my new mattresses.
Otherwise a steamer should do the job and leave them outside to air dry before you put them back in. There are some recent posts here on reupholstering if you take that notion.
