Is it going to touch the food?
If not I would use Sil-glyde. Akin to what the first response suggested re: silicone. Good for that but not food grade, cheap, readily available, and other uses.
There was a thread in the food section six to 10 weeks ago (?) re: grease for a Kitchenaid mixer and attachments. Hunt that if you can as there was a lot of good ideas IIRC.