Thanks so much for these suggestions!
I'm not sure if I can get these exact products here in South Africa, but I will go to the various stores on the weekend to ask.
Do you guys perhaps know what the active ingredient is in these products that makes them effective? So I can try find a local alternative that is similar.
My affected pony started itching last winter (the first winter I had him), I thought then it might be a dust allergy (very dusty dry winters here!), the vet was summoned and he got a cortisone shot, which helped, but didn't clear it up. She personally doesn't believe in herbal supplements that work, hence I am asking here... Anyway, come summer and no improvement, so there goes my dust theory. Another shot. Same story. I've tried topical liniments daily with a bug spray. Again, it helps but doesn't clear it up. I bought him an expensive fly sheet last week as a last resort, knowing what would happen; he tore it to shreds within a few days.
I am at my wits end!