I use Neem oil.
Last summer i had the sliding doors in my "greenhouse" open and normally there should have been a lot of insects in there as well. A few bees and a bumbelbee flew in, turned around and left after a short time. There was no signes of any other insects there at all, and no damage to the orchids. I have had problems with scales, spidermites and mealy bugs before, but not after i started to use Neem oil.
Neemoil/dish soap/water is easy to mix if you shake the watercan and use tepid water and i spray all my plants about every 14 day from april to september, when insects are active here.
The smell is a bit strong, but i can live with that and i move the plants outside when i use it and never use it inside my appartment.
It is also important not to pour the oilmixture down the drains, because they can get clogged.
A bit OT but i bought a shampoo with neemoil for my dogs and none of my dogs had any ticks last summer
There is a lot of info. on the web about Neemoil and its positive (and negative) effects and the climate where you live might also give different results from what i have experienced.