I posted this over in the Guitar section, but this applies to both bass and guitar, so I'll post it here for those who don't swing with the six-string...
I just found a jar of Winsor & Newton "Artisan Water Mixable Linseed Oil" for oil painting.
I'm not sure if it's just oil, or if it has any other ingredients that might be harmful to my guitar. I do know that it's oil based, and not water based.
Have you guys ever used anything like that?
What do you use?