Aeromarine grommets i used and then shoot end of grommet with sealer and then nylon tied it and havent had a drop come through.
ones for ant wire and another is for the 3 wire servo wire. both not a drip.
these are the grommets with the 3 screws to screw it down, I silicone around that as well, the push in and glue in ones are junk, never had good luck with them.
Tom