I like it. Or you can use 50 feet of 1/8 inch diameter dacron cord and a marlin hitch. Cut 2 pieces about 2 feet long for outhauls, then find the halfway point in the cord and work out each spar from the interlocking bolt.
Zip (ratchet) ties work fine and are easy to attach and cheap enough that you can just cut them off if you need to remover the sail. Just make sure there are no sharp edges to the ties if you trim the excess plastic as they could chafe the sailcloth when rolled up. Consider rounding the plastic ends with a little sandpaper.
Zip ties are an ingenious idea. They are cheap, strong , and much easier to deal with then the shower curtain rings.
Although I went with the marlin hitch that signal Charlie recommends myself, also relatively inexpensive, easy to remove and reusable.