Just use crimped fittings or hemp.
Incidentally, before Teflon tape became affordable enough for plumbing use, most plumbers were using a type of traditional "pipe dope" instead.
Maybe this is another application where it might be a feature if "dope sells itself".
That’s the traditional way of sealing joints. No chemicals, just hemp and your own saliva (you usually don’t have running water nearby when doing plumbing).
Sometimes chemicals are safer.
Between 1986 and 2011, lead free plumbing can contain up to 8% lead per EPA standards. After 2011, lead free plumbing may now only contain 0.25% lead.