Idk how to describe WD-40 cus its a really weird product. It's like a bandage, really good for when you need something quick, but nothing more than a stopgap for a serious injury.It isn't ? Then what is it ?
WD-40 themselves state that "....protects metal from rust and corrosion, penetrates stuck parts, displaces moisture and lubricates almost anything"
I'm sure WD-40 is guitar safe, but I wouldn't recommend it as a long term lubricant solution for anything. It will become ineffective far sooner than you change stringsWD-40 seems like it should be guitar safe since it’s believed to be mostly naphtha, which we know is a great solvent (I detailed my motorcycles with WD-40 for years), but I might test it on a guitar that’s not so precious. I would think the Dunlop 65 string conditioner should work - just daub it on there.