The only experience I have is sending to Paris for dry cleaning and repleating. As another poster wrote, Hermes does this all the time and they have a box on a requisition form to check off for plisse. I would be afraid to bring a plisse to my dry cleaner even though they handle Hermes scarves with the rolled hems all the time. Tie Crafters in NYC may also clean plisses- Hermes uses them in the US.
Thank you toujours*chic

I rang my local Hermes here in the UK and they said they send to Bond Street in London who deal with the plisse cleaning - as per Bienchen's note above.