I have been itching for months now from Lichen Planus and tried many of your hints which all work for a short time. However I have discovered something that seems to work better. This hint came from a Nurse Practitioner in a Dermatology office.
When using steroids ( I have cleobesterol which didn't seem to help much) apply the cream and then on top put a barrier! This can be something like a product with silicone or glycerine ( silicone glove, others) or just plain glycerine. This helps the steroid stay and do its work. I felt the itch much relieved after 2 days of doing this. Give it a try. Hope it helps.