Maybe storing the baits in something that is not oil-based would help. (Oils eventually dissolve soft plastic baits. Trust me, I tried it.)
Perhaps vacuum packing them in coffee grounds?
The liquid from a can of water-packed tuna might be good, but the package would need to be refrigerated or frozen. Hmm... I wonder what happens to soft plastic baits when they are frozen? Boil some shrimp, let the water cool, add some soft baits, then freeze. Could be a fun experiment.

Something simple like sea salt mixed with distilled water & a little garlic powder might work just as good.
Even though these soft baits have a chemical smell, they probably catch fish, but they might not work as well as a more natural smelling bait. ALL soft plastic baits smelled bad back in the 70s and 80s, but they still caught fish. Scented/salted baits are relatively new. Since many of the bass out there have been caught & released, they probably learn very quickly that certain smells indicate danger. Bass are intially attracted to a lure by sight and/or sound, but when they get close, scent becomes a factor -- especially with a slow presentation (tubes, senkos, jigs, etc). They might rush in quickly and then abort the attack while thinking "whoa baby, what's that smell"....
What do you guys think?