When my ds has been scratching badly, I've been perscribed some antihistimine, piriton, for him to take at night.
I found this really helpful as it just stopped him scratching enough for him to start healing.
Also for hydrocortisone I like the fucident h as it also has an antibacterial agent. I find that far more effective than the regular hydrocortisone.
Think with excema there is a lot of ignorance and you quickly get very weary of what people tell you. My Mum was told by one chemist that the only treatment was E45 - that actually aggrevates many childrens excema.
Personally I like epaderm - good thick lardy stuff. I've also found covering ds's entire body in sudacreme to be very effective.
Hope you have some luck soon. It's just a matter of finding waht works for you.