....why not enclose a plastic bottle of high grade oil approved by the manufacturer for these boards?
A small 2oz bottle would be great for the initial application to a new board, OR give the option of a larger 8oz size that would enable users to reapply over the years.  They could charge a little extra for the 8 oz bottle but the 2oz bottle should be complimentary and save people from hunting it down at one of the big box hardware outfits.