Here is some old time scent tricks before the modern smelly sticky formulas in a bottle. Many of the commercial scent jellies and pastes are outstanding attractants.
Vaseline Balls
This is a old time bait substitute.
Scented Jelly paste
Place spoonful of Vaseline in film container and melt in microwave. Now add scented oil of choice and stir. Chill to setup mixture. Seal container and go fishing with your new scent . When using fresh bait remember to keep it cold when not in use.
If you have access to a freeze drying system you can preserve your bait with out the need for refrigeration. This will make for some really concentrated scents.