I have tried a recipe that works great and doesn't dissolve straight away, I used gelatin and glycerin in a 1:1 ratio (heated in a pan until gelatin has dissolved) to cast the lures then after letting them setup in the freezer for an hour I sit them in a solution of 1tsp tannin to 1 cup water this stops the lure dissolving so quickly this mixture gives a firm yet flexible lure hopefully this is what your all looking for also at molten stage you can add liquid food colouring/flavours
I have another recipe I'm trying out that could be even better and uses really cheap and easy to get ingredients glycerin/gelatin/water/honey (2:2:1:1)