I’ve heard of them. Seen videos but never tried them. With the current prices of quality “disposable” lids, these become all the more realistic priced. I know of people that keep these in LTS for after a crisis when the disposable lids are no longer available.

"Government at its best is a necessary evil, and at it�s worst, an intolerable one."
 Thomas Paine (from "Common Sense" 1776)