I use this for my MIG torch. Works great and definitely cheaper.
I assume it would work just as well for plasma cutting. Never thought to try it but I am going to later today as a result of reading here and I have occasionally had a piece of slag partially block the opening in the tip.
I usually dip it right after I make a weld so its hot and melts and coats real well.
Hobart 770074 Welding Mig Accessory Nozzle Gel - Arc Welding Nozzles - Amazon.com