De earth, cheap organic and available at most hardware stores it will kill any bug with an exoskeleton, it's fine powder so you have to have dry topsoil, sprinkle around the plant and again make shure it's dry, leave 72 hours give a light flush check ph and you should be good, i have used it to kill off those gnats or fruit flys or whatever they are, allso cured plants of thrips, you never want to put poison on your plants, de earth is completely organic.
"not crazy amount"shortly becomes crazy amount!:D
You could use hot pepper tea,garlic(if they are in veg),black pepper,tobacco,rosemary,lavender,onions and more and more you can think of:)If i were bug i def couldnt stand all that haha I dont use the soap,its for the remedy to stick to the plants but i dont know how harmful is it.......But once or twice in veg if needed wont be a problem to add it.In flowering i would use only hot pepper tea,may be canela but garlic,tobacco and such could be inappropriate:)
And everything in your environment should be cleaned as much as possible or the pests could comeback.Closest plants should be removed as possible and checked(sprayed to if needed) and things like these so they can be fully destroyed.