Before getting into bait manufacturing we worked 20 years in the paintball industry. In the early 2000's RP Scherer tried using the corn starch based plastic/gelatin mixture. It worked well, but water would still break down the shell over time just as if they were using straight gelatin. About 8 years ago there was a start up company called Hydrotech that actually developed a plastic that could be used with a full water based fill & not break down. It instead relied on bacteria to naturally break it down. The company lost investors & never made it off the ground but I do know one of the guys that was there during the development. I may have to send him a message & see if he would share what type of plastic they were using.