The only thing I have found that works completly for my horse is her Boet Blanket. They are expensive to buy buy have found if I put it on early spring till winter I have no problems at all. Definately worth the money.
I know, have gone for the 10 jump set and cant believe what a bargain it is! Only £36 pounds for delivery too..... most of the other sets I looked at were twice the price and around £150 for delivery- am very happy!