I use Rector Seal #7 for this type of application. Works great and doesn't leak.
Hate using that stuff...like anti seize for me I get it everywhere
Any how... As a guy that works in the oil and natural gas industry I use Teflon tape daily. Use it on air lines, nat gas lines, natural gas liquids, condensate liquids ( think drip gas), lube oil lines, glycol, anti freeze ect.
Only things I use other than plain white Teflon tape is rector seal (which I hate using but works well with Teflon) or gray tape nickle/Teflon thread tape that is like anti seize and Teflon in one. It is great for stainless fittings, which I use a lot of.
Biggest thing I can say is apply it right with " enough" tape (which "enough" is in the actual procedure) generally 3-4 wraps of 1/2" wide white Teflon does the trick on smaller pipe fittings...and get it tight!! this is holding back up to 1250psi at times easily