Hi,
I'm afraid I have no experience of Charcot, but I recently heard about a form of exercise suitable of people unable to stand.
It's called a bodyblade. Looks like a stick, and you waggle it in a very small movement range, in a fixed position. It causes the muscles to contact and release very quickly, like one of those very expensive vibration machines at gyms.
Created by a physiotherapist, I think.
Sold on Amazon and qvc (just did a google search), so you should get some reviews there.