Nail polish itself is fine even with salicylates in it because it sits on your nails which do not absorb the ingredients.
HOWEVER, if you get any nail polish on your skin around your nails or cuticles that will block your Guaifenesin. If you get any on your skin or cuticles when you use the nail polish remover (also check for sals) that will block. Some nail polish will have castor oil in it, so watch for that. I have heard that recently Dr St Amand believes someone to have blocked on nail polish, applied messy, so getting on fingers. (Sept 2 2016)
Nail Polish remover also commonly has sals in it. Make sure to check the ingredients. This one is sal safe (no plant oils, gels or extracts and no sal, camph or menth) Pretty nails with Acetone, Agua, fragrance
Here’s the link to a list of Nail stuff that is currently sal-safe, as usual double check the ingredients on each item you buy as ingredients can change without warning! 🙂 http://www.fibrofreerecoverygroup.com/salicylate-free-product-list/#nails
Check post on FAQ of Guaifenesin Protocol and Salicylates