Why haven't you just stopped her? Or at least taken the scrubby out of her hand and told her that it scratches the glasses?
If you can't stop her this year, take the scrubby completely out of the kitchen. Have appropriate cloths out in the open. When Sally starts in cleaning, just go into the kitchen, try to persuade her to leave and if she won't, hand her the correct cleaning cloth. If she asks for/looks for the scrubby, tell her the truth. That the scrubby scratches the glasses and you'd prefer her to use the cloth you've given her.
I have tried. She won't take no for an answer. I thought hiding it would work, but guess not. Next year, I will have to remove it completely even though I had a soft cloth rag in plain sight.
How direct are you? Don't be "nice."
Don't say sutff like this:
you need to lather rinse repeat: "no, please leave the dishes and let's go back to the kitchen. no, really , leave them. Come, let's go find the coats".
if you can't then how about redirecting - "Sally, please don't wash the glasses. they go in the dishwasher. no, put the scrubbie down, i just stack them as is. thanks!"
Be very, very direct.
Don't make it be about how you don't want to trouble her. Make it a direct order. "Sally, those are my wineglasses. Please do not wash them with that scrubby---it is way too harsh for them. They are my glasses--if you want to help me, you need to wash them with this cloth right here."But better yet, skip the scoldy parts and steer her.
It's always nicer, and often more effective, to tell people something that you *do* want (glasses washed with *this* tool) and not what you don't want (you damaging my glasses by using the wrong tool).
It's easier to dig a new channel for a river than it is to stop it up completely.
Get a sponge that's appropriate for the glassware but that looks as much like the other scrubby as possible in terms of size and shape. Then directly ask her for help, instead of leaving it to be the sort of thing she would do "behind your back," so to speak. Say, "Sally, would you help me with the glasses again this year? That was really helpful. However, I need for you to use this sponge here, because it's appropriate for glassware. Last year I didn't have it, and you used the one that's intended for pots and pans, which is far too harsh. I want to keep them nice. It would be so helpful to have a few of them clean."
(I will say that since I'm used to using a scrubby sponge of some sort, I find it awkward to use a cloth; I fear I will break the glasses since the cloth is bulky, and it feels awkward. Maybe Sally is the same--so seize the thing she keeps wanting to do, and mimic it as much as possible.)