Hi Mike,
You can use the main halyard or a trap line ... both will work. You discribed the technic perfectly.
I use the main halyard since I'm too lazy to undo my trap bungies and sometimes I mistakenly let the bungies go and "zip" into the hull they go on my P19, so you need to re-string the bungie through the hull ... which sometimes takes a straightened "coat hanger" to fish the bungie through ....
Harry