It couldn't be lighter fluid could it??
With a spark it makes a great hair trimmer. Take it from me. 
I'm keeping my dome bald to help with some skin issues, and doing that would only help with exfoliation.

I'd probably get better results with an electric shaver, but the salespeople are rather reluctant to let me try them before buying, and most are too weak to deal with my short stubble.

Funnily enough, I've always got two completely different type of hairs on my head and face: soft and thin ones, and really stiff slightly darker ones. I can easily stall any trimmer I've tried by just pushing it into my hair, whenever it's longer than a few mm. (Also happens with "pro" gear at barbers/hairdressers.) Keeping the trimmer blades clean and lubricated really helps.
(I have tried different lubricants, but they're too sticky. Thin unadulterated mineral oil really works best.)
I get best results with a sharp safety razor, of course, but the blades get dull real fast; much, much faster than shaving my beard (even accounting for the "work area"). And when dull, the blade starts to rip, which I really dislike.