I've about had it with scale on my guava and sapodilla trees, until Last week. I tried something not poisonous, herbal or harmful in anyway and am going to continue my treatments weekly to rid myself of it.
What I found out that plain water from the garden hose delivered by one of those brass $5.00 high pressure water nozzles while supporting the branch tip with my hand blows the scale off easily while not hurting the leaves or branch. It also cleans off the sticky goo.
I don't plan on spraying with neem and detergent anymore.