I agree with Endiku. Each horse is different. I have 3 tb's, one is much more sensitive to which grooming tools he prefers.
You could experiment with which style of curry and brushes your horse prefers and then just use those ones for him, you will also have to experiment with the technique you use, just how much pressure he prefers. Sometimes if you go too lightly it can be more irritating to them than if you use a bit more pressure. Just try different things and see what works best and then give it time, he may start to enjoy it more.
Some good styles of rubber curry to try would be a rubber curry mitt, like Endiku mentioned, there are a few different variations of them with different style nubbs that would work, but the regular basic one is always a good choice.
You could also try one of the soft rubber curries with the soft fingers, like the Oster Fine Curry or the Grooma Soft Touch Curry or something else similar, there are lots of different kinds like those ones.
I also find that the traditional regular oval style of curry comes in a hard rubber that isn't very flexible or a very soft rubber that is very flexible. My horses all prefer the soft flexible ones. One of the brands that makes a very soft flexible one is Equi-Essentials. Victory Canter English Tack & Apparel
has the Equi-Essentials soft rubber oval curries, the mitts and a Velvet Touch curry that is just like the Grooma Soft Touch curry.