I honestly hadn't heard of CHS until today (for those who don't know: https://goo.gl/XuXLhQ). I know that neem oil is used largely across the state of Colorado for pests. If people are having trouble with these symptoms I usually recommend CBD or hemp oil as the concentration and growth methods are a little different. Honestly, if you find somewhere that grows good cannabis and has a relatively sanitary grow, they shouldn't need to use neem.
Though, the best way to get a plant that clean is to grow it yourself, unfortunately. Or take a tolerance break (shudder)