True, it's much less concentrated, so one needs to use much more. See below.I have not used it either but it has the same active ingredient as Elector PSP, Spinosad (A mixture of spinosyn A and spinosyn D) (44.2%) per 8 oz. Captain Jack is 0.5%.
Elector PSP made gallon
1 ml = 442 mg
~9 ml per gallon
9 ml Elector + 3776 ml water = 3785 ml (one gallon)
9 ml per gallon x 442 mg per ml = 3978 mg spinosad per gallon
I think that works out to a dilution of ~0.1% spinosad per gallon.
The above should be the reference when trying to make other spinosad sprays. Target amount of spinosad per one gallon is 3978 mg or 0.1%
Captain Jack's 0.5%
1 ml = 5 mg
795.6 ml per gallon
795.6 ml per gallon + 2989.4 ml water = 3785 ml one gallon
795.6 ml per gallon x 5 mg per ml = 3978 mg spinosad per one gallon