i think there is liquid teflon... you apply with a brush... messy! just stick with tape.
as far as plumbing.... for speed put your fill valve on the straight end of a tee fitting... dump on the 90 degree part of the tee... and your other straight to the bag... this way you have straight through flow of air to the bag from your fill valve. a 90 fitting or direct bend in a tee is equal to 7-8 feet of line... restriction.