Ooh, have a link so I can see what it looks like?

I’ve been using the metal ones for years, but only recently found a way to clean them. I hold them with pliers and use a small blowtorch (the same one I use for heating resins.) It burns up the residue surprisingly quickly. It does make a bit of a smell, and since the metal gets super hot I’d recommend doing it over a sink for safety, but hey, it works.