I've got to be honest, I suspect you 'pure lemon oil' is cut with something - concentrated limonene, the main component is easily flammable and causes contact dermatitis as well as killing fish.
But most of all, if you used enough to cover a fingerboard your bandmates would be saying you smell like a washing up liquid factory!
Whilst 'food grade' lemon oil is pure and concentrated lemon oil as sold in supermarkets for cooking is cut with vegetable oil:
https://www.tesco.com/groceries/en-GB/products/289599286
Tesco Sicilian Lemon Extract 60Ml
Ingredients
INGREDIENTS: Rapeseed Oil, Lemon Oil.
Personally, my worry would be that vegetable oils (as opposed to mineral oils) are more liable to oxidation and becoming sticky and horrible.
Actually, would you be kind enough to share a picture of the lemon oil you use?