A good organic method that I use is Dr. Bonner's soap (I use peppermint, weed and peppermint smells awesome to me) in an Ortho hose end sprayer. I set the adjuster to 1 tsp/gal and dilute the soap in the container with water. I then spray the plants thoroughly, giving them a good detail job. I wait 10-15 minutes and thoroughly rinse with clean water. Works pretty good for me, the plants are happy and clean. I also do this prior to foliar apps. The soap only works on bugs when they get wet with soap/water mix, it also functions as a surfactant when wet but soap acts as a desiccant when it dries, so I rinse it off. I foliar feed and water regularly.