Hi,
I like your lacquer idea.
I have taken a different route. As I also whitewater boat, I carry two lighters and two separate packs of matches, well wrapped up. The matches are only used in an emergency and, as long as they stayed wrapped up, they seem "water proof" (numerous swims have confirmed this) enough. Regarding lighters. The style you get in camping and RV stores with the long necks suck when just slightly damp from dew where cigarette lighters (with a flint/steel) work fine....other than your fingers get singed when lighting stoves that is.
Steve