Question about using Neem oil as a drench

[zygostates]

Hello,
I am an inside/under lights orchid grower. In Fall, I move the orchids inside in the basement. Despite preventative spraying for a month before moving all of the orchid inside, I have had a mealy bug and red spider mite infestation. I would like to use Neem oil in order to avoid commercial insecticides off gassing in my basement. I have mealy bugs in the media in some of my plants. I was wondering if I could use neem oil not only as a a topical application but as a drench application as well. Has anyone done this before with success? What would be the application ratio?...is it different from the topical ratio? Also..Is the DyNaGro Neem Oil different from the Cold Pressed Neem Oil that is used for skin applications?
Thank you
Glenn

[Ray]

Good, fresh, pure neem oil should have at least 1400 ppm azadirachtin, the active ingredient. The Dyna-Gro product is probably close to that, but I cannot speak for the cosmetic version.

However, I highly recommend against using any kind of oil as a drench, as it will be absorbed by the velamen on the roots and totally clog it up, forcing your plant to wait for it to decompose before its roots will be fully functional again - if they survive that long.

[Mervin]

If repotting for all your plant is viable, I suugest you do that.

Carefully wash all your plants with insecticidal during repotting also helps.

Mites.....once you have them, its almost impossible to completely get rid of them....