Not sure if the RHD grommets are located in the same spots our LHD rigs are.
Also be careful when you push the sharpened hanger thru the grommet to not dislodge it. It is tough to get back in place. Been there, done that.
If you tape the wire to the end of the hanger and pull it thru the grommet together, the rubber grommet has enough ply to seal around the wire. Also if you poke the hanger thru at a slight upward angle from inside the engine bay, any water that gets on the wire will drip out, not into the cab. Once the wire is thru the grommet where you want it, pull it back into the engine bay a little. This pulls the rubber outward around the wire to form little "lips", for a lack of a better word, for a better seal.
No extra sealant needed that way.