Your site indicates that the soil in potted outdoor plants can be debugged by submerging the pots in soapy water. What kind of soap should be used? How strong should the solution be? How long should the plants/pots remain submerged? Should the soil be "rinsed" with clear water after submersion? I assume that the plant itself (above the soil) can be treated with a commercial insecticide like neem oil. Thanks for your help!