Is there anything better than lemon juice to get walnut stains off your mitts?
This sums it up so what's the problem. I have gotten the stains many times even when doing flat work with dry red oak and never had any ill effects.These are harmless stains (within the skin, not on the skin) that'll fade away after a couple days with normal washing/bathing and skin sloughing, and those other chemical ideas will do far worse to your flesh.
Sounds like a good excuse for making lemonade or margaritas depending on your inclination.Lemon juice works great. Lime juice in a pinch. No need to look further, IMO.