Try it. See if teflon tape survives torquing to 70Nm. I suspect it'll get shreaded. The next thing is temperature. A cylinder head gets far hotter than typical home and business plumbing. A quick internet search shows teflon tape is good to 250-500*F (take your pick). I would think a prechamber routinely sees 250*F, though maybe not 500*F.

Sixto
87 300D^2