For years I've used tobacco tea as a pesticide of last resort, when other measures prove futile. I make it with cigarettes, chewing tobacco, or home-grown exactly as one would make any tea....bringing it to a boil in
water and letting it steep. I like to make it strong and steep it overnight, then dilute with water and a bit of
soap to encourage it to stick to plants and insects. It is quickly lethal to just about any insect, and, as you surmise, is not for use for quite a while pre-harvest of food crops, nor for plants susceptible to tobacco mosaic virus.....all nightshades, at least.