Pretty much, yeah. It's very simple.What do you do then, just fill the PET bottles up from the bottom through the carbonation cap + beer line? Presumably the cap is loosely fitted to let the air / gas out or you just unwind a little when the flow slows down. Do you purge the bottles first? Interested as I have a couple of boxes of Coopers PET bottles that I hardly ever use and it could be a useful thing to do for taking beer on holiday. I also have a carbonation cap and beer line!
Clean and sanitise your bottles.
Same with carb cap and line.
Screw on and hook up the gas.
Loosen the cap to purge.
Attach bottle with carb cap to a pre cleaned and sanitised (and purged) jumper line.
Hook gas up to the keg.
Slowly release the pressure from the bottle to fill it and tighten when full. Let a little bit of beer escape before tightening.
Remove carb cap.
Squeeze bottle in order to 'cap on foam'.