Dave Plowman wrote:

Wrapping the olive with PTFE will do no harm. IMHO it gives a better
chance of a good seal too. And unlike any other sealer gunge doesn't go
off in storage. Or make a mess of your hands, etc. And is very cheap.

Hemp and boss white was never used on any compression fitting I've ever
seen.

I don't routinely use any gunge on compression fittings, but have used
LS-X on problem ones (both copper and plastic waste) to good effect, it
has a very long shelf life.