Send a message to Leather CPR about their product and here is the reply that I received:
Thank you for your email! Leather CPR is the only leather cleaner and
conditioner on the market that has been dermatologist tested, and safe when
used on leather items that come in contact with skin.
As far as using it on earphones, that's a first for us. I really depends on
how sensitive your skin is. If you have highly sensitive skin, we would not
suggest using it.
Please let us know if you have any other questions.
CPR Cleaning Product
I was interested in using your Leather CPR to care for some Lamb Leather ear
pads on a higher-end pair of headphones.
Is there any information available concerning the use of the product on
something that will be in contact with the skin for prolonged periods?
Basically the recommendation I gave. Seeing as their probably aren't many other products that even claim to have done testing, this might not be a bad way to go.