Q.Orange tree scale
When you say ” Spray every five to seven days as needed, covering both sides of the foliage. Wash the leaves individually with the soap/oil mixture and rinse well.” do you mean to rinse well after every spraying? Also, how do we rinse, with a light spraying of the water hose?
We recommend Neem Oil for a treatment for the Scale pests on citrus.
These links will help you.
https://www.gardeningknowhow.com/edible/fruits/citrus/controlling-citrus-scale.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm