This is the one that I got off this board. Don't recall who posted it but thx to whomever did. I like it. Here it is word for word:

1 gallon distilled water (or clean creek water, just no chlorines or iodines in it)
1/2 box of baking soda
16 oz peroxide
2 shot glasses of Hunters Specialty green liquid soap

Pour out enough water from a gallon jug to get the other stuff in and let it fizz for a while after mixing (about 1 hour or the top will pop off). Then just transfer to a spray bottle and you're set.

Note: Use an opaque bottle to make and store it in. Apparently, peroxide turns to water when light hits it, a fact I wasn't initially aware of.