I would be worried that anything that would soften the rubber would attack the glue that holds it on. Probably causing more problems then it would fix.
The oils in the rubber will leach out no matter what you do. The best thing you can do is keep them out of the sun and heat.
For what it is worth I have worked in the polymer industry for 15 years and designed a handful of elastomer products, though they are not my specialty.
The oils in the rubber will leach out no matter what you do. The best thing you can do is keep them out of the sun and heat.
For what it is worth I have worked in the polymer industry for 15 years and designed a handful of elastomer products, though they are not my specialty.