The spray bottle form is for immediate results, spray the whole plant to hopefully hit the bugs, and they are supposed to die within 48 hours, it dissipates away within 24hrs, so they recommend a treatment every "like" 7 days if I remember correctly. I myself did 3 treatments over 3 months, since I'm doing an indoor grow. I also bought the dust/powder version and dusted my soil on my plant that's on the patio. But I also had good results using mosquito dunks to kill the soil critters.
I went the spinosad route because there's supposedly no nasty after effect's compared to what I read about Neem Oil making buds taste bad. Plus spending 40+ years in a machine shop environment, I know that oil is a dirt magnet. I didnt want oily leaves or buds. Oil doe's not evaporate, it just basically dilutes over time from dirt collecting on top of it.
