Why isn't vegetable grease preferable to mineral grease? I mean for treating wooden-handled implements such as knife, guns,etc.?

I mean for treating wooden-handled implements such as knife, guns,etc.?
You know that tv commericial for Dawn dishwashing...
Answers:    No, vegetable is necessarily not preferable to mineral oil for treating wooden handle implements because it can go rancid.
Mineral grease is used because it doesn't spoil.
Still inevitability laundry give a hand?
Mineral oil is derived from the land by oil refinery, therefore, nearby are trace metals in the grease which helps to lubricate metals and wood surfaces.

Vegetable grease is derived from plants and has some silicone and glucose within it, that is what make it tacky. It will work within a pinch, but it will eventually build up on the surface and will need to be removed entirely.