I've never used one! All the boats I've been on we had to pull the jib and bag it. My grandpa (mainly to show off) would have us reef the main and then sail us around on the jib for a while, but we rarely dropped the jib and went under main alone. The couple of times we did, we just reefed the jib to itself, settled it on the foredeck and used the sheets to tighten it down (enough).
Seems like a big apparatus on a 15' boat.