No to the Scent Killer formula, but if you care to share it, we'll acknowledge you for sharing it.
I found that Ace Hardware (and the Net) sells "High Yield 38 Plus" bug juice in 16 ounce bottles containing 38% Permethrin. It isn't expensive (~$27.99 a bottle
http://stores.ukillem.com/Detail.bok?no=24 ), but diluted to 0.50% is 9.5 gallons of solution as below:
HI-YIELD Permethrin
16 oz (equals 0.125 gallons)
x
38.00% Concentration
equals
6.08 oz of 100% Permethrin
Divided by
0.50% concentration of mixture
equals
1216 oz of 0.50% percentage mixture, which is 9.5 gallons @ 0.50% percent Permethrin.
If you find Permethrin in other concentrations, substitute your concentration into the sequence above.