Better living through chemistry is always a good topic 
My super simple flaming tye dyed bandanna recipe for mites.
About 2ml of olive oil, a few drops of detergent and 250 ml water is lethal when sprayed on spider mites, aphids and scale. It is surprisingly more effective than some other essential oils like clove and rosemary and even hash oil was tested in the study I read. You have to do it at lights out, but I have never burnt them as with neem and it is effective at control. TBH having grown outside in the tropics where the insect load is off its head, I found two weekly treatment with neem was just about as effective as anything, without me being paranoid about poisoning anyone.
Fungus and septoria treatments however, chemicals all the way, though I would typically double any withholding period and minimize use during flower.
Interesting, I wonder by who and how that safe threshold is defined? In principle even if there is minute traces in clones after using chemicals you have to think it’s going to be so little that when distributed in the flower mass it’s not going to be a health hazard, at least not when you consider the food we eat, milk we drink is farmed using the same chemicals.
It’s fine for them to say the chemicals are for AG but growing weed is……kinda AG? and if it’s good for our food/milk you gotta wonder what’s the difference?
A lot of pesticides/herbicides degrade with exposure to UV light, rather than photosynthesis, so that might be the difference indoors. The other thing is that a lot of pests/weeds have developed pretty good resistance to a lot of the chemicals typically used to treat them, so multi spectrum treatment is normally more effective, but you just need to establish compatibility first as I have learned the hard way by killing everything, including a whole field of crops one time lol.