They make the bait last longer but may not give the same action on the fall.
Essentially this, o-ring will definitely save you money but "may" result in fewer bites.
??? cost of O-ring tool and O-rings vs the few extra baits you may have to use ???
I bought one of the tools and then went back to hooking it straight thru the bait.....
I also tried using small zip ties in various neon colors ...... if chartreuse dye on the tail will work I figured a neon colored zip tie instaed of the o-ring might work as well. You can snug the zip tie up so that the hook does not come out when "zipping" it under a dock .... did it help and get more bites,,,,,,I don't know .... didn't do a scientific study ..... but I still use them when flipping under docks. for weed beds and rocks I just go thru the stick bait with a weed guard hook ... usually a Gamma #3