Mealy Bugs
Thank you for your post. Only one caution when using Neem Oil. Use in morning or in late afternoon and keep plants out of direct sun. It can cause sun burn. Also protect your skin. Glad to hear your success.
I have recently started using a dilute solution of Ajax dishwashing liquid on anything that looks like it might be a bug. It works very well on scale as well as mealy bugs. I use about a teaspoon per quart of water. I have a spray bottle ready at all times. Dishwashing liquid is also pretty safe for us to use. It is also cheap.
I am going to try your idea of the Neem on my redwood benches. The oil may last longer than just soap.
Happy growing!