I find rayon very hard to predict, so I'm hesitant to suggest you wash them. If they happen to be your favorite pants, still in the prime of life, then I might say keep on dry cleaning them.

OTOH, you could try literally handwashing them in a basin, followed by a spin the machine to remove the water and hanging to dry. If they do OK there, you could then try a machine washing cycle. Handwash designation or not, a machine will always be more challenging than a few swishes in the sink.

If you do wash them, I would use a special detergent for dark colors; turn them inside out before washing; use cold, or at most cool water to avoid shrinkage; and NEVER machine dry them. Of course, you will have to press them, which some people find so irksome they'd rather have the dry cleaner handle that anyway. If they are lined, all bets are off, and I would dry clean them as the lining may be the snag with water washing, and anyway pressing lined pants is a complete pain.

Sorry not to be more unequivocal. Rayon, although made from natural fibers is just a tricky material, but it has a lovely linen-like drape.

Molly~

Oh man! They are lined, didn't even think about that complicating things :(

Thanks so much for sharing your knowledge. It will be dry clean only for these pants.