Do you rinse off insecticidal soap?

I keep getting a white fly infestation. Bastards ALWAYS find their way onto the big ass fan leaves at the bottom of the plant. Nasty whole underside covered in either egg/larvae or whitefly shit. Probably eggs. Anyway, last time I used it they were small, too small i guess. It almost killed them. Anyone know if you are supossed to rinse this stuff off or leave it on there since you are supposed to re-apply after 10 days?

Thanks