I've never used Kontos for RA, but have used it for other reasons so I can tell you this much...
Dosage is 1ml/gal...
It doesn't negatively affect the plants at all IMO.
I don't know how successful it is as a knock down RA, because from what I recall that's not exactly how it's designed to work on any pest... More so as a preventative or to be used at first sign of infestation. So would probably be best used with another, contact killer sort of thing if you're going up against a major infestation.
But that's not to say it doesn't rip RA a new one, someone that's used it for that purpose would have to chime in.
If you decide to use it, just be sure to read the label thoroughly to understand how to use it, and not over-apply.