Oily Utility Sides - Will They Stain Cloth

[Eldorado]

A question for the wise and experienced folk here.

I'm thinking of using Tandy's Oily Utility Sides or their Stoned Oil Cowhide sides to make a shoulder strap. Does anyone know if the oily stuff is prone to escaping the leather and getting on clothing (like the shirt the strap is rubbing against)?

I've not used this material before and like the texture, but don't want to get calls from customers griping about how it ruined their clothes.

Thanks in advance for any advice and assistance.