Just to note as the above solution does not mention it.
You unlock the sleeptite recipe by working through Sallys main quests specifically completing squaring the circle
Once complete you unlock the ability to craft sleeptite and sleeptite atomizer which are under the Chemicals branch and tools branch respectively.
I found that unlocking the skills Double, Double under Super Duper branch and Craftsman under the survival branch really helped, the double skill has a chance of creating items twice while the craftsman skill means created itsms last 50% longer.
Make sure you have been collecting lots of plants foxglove seeds and nonsuch plants and lily bulbs. (you can find spades at the backs of the houses in the village)
i was getting around 7 sprays from each atomizer. I recommend crafting around 6-7 atomizers. , I headed to Maidenholm I angered the people until I had groups chasing me, I then sprayed when I was near a group. The most people I saw drop from it was 3 however most of the time it was dropping 1 or 2. I had the achievement within 5 minutes.