What you need: Toothpaste, Towel, and water

I decided to use old towels and Arm & Hammer toothpaste.

Put the toothpaste on your towel and start scrubbing really in whatever motion you decide to.  Your headlight should start to become clear. The debris should start to come off into your towel.  Now all you need to do is rinse your headlight off.  This is much more affordable than store bought kits