Q.Hibiscus seems sick
The Hibiscus I recently bought from the small nursery across the street seems sick…buds are falling off, leaves are turning yellow and blossoms are grey and crumpled. I saw some small insects and sprayed the entire plant with a plant based dish detergent, white vinegar and water. Saw on the internet that Neem was inappropriate for the Hibiscus. Please Help!! Thanks..Jewels

Due to the presence of vinegar, the spray mix you described sounds like a herbicide spray (for weeds) and not an insecticide spray. Did your plant see a decline after you sprayed it?
I would say the insects were probably thrips or perhaps even gall midge. Both insects would cause the bud drop you spoke of. Here is an article with more information: