Generally-speaking, if you really want to use some form of wax, I'd just say 'simpler is better' (in terms of ingredients). So, if you can verify that the wax doesn't contain other stuff that might be acidic or caustic (strongly alkaline, at the other end of the pH scale), I'd think you'd be OK. Don't know if any bar soaps still contain lye or not (many did, at one time), but that's one of the 'caustic' things to avoid, if it's there.
Personally, I think a clean mineral oil-soaked rag/cloth is as good as anything. Carry it in a zip-loc bag, and use it only after cleaning the blade, so the rag doesn't become contaminated with rust-making stuff. OR, if the lip balm idea still appeals to you, I'd personally favor the 'original' Chapstick. It relies on mostly petrolatum (petroleum jelly), and some other ingredients including mineral oil; not so much of the other 'natural' food-sourced stuff that may be good for skin, but maybe not so good for corrosion-prone steel.
David