A good farrier or trimmer will tell you the best thing for a horse with a club hoof is to trim him to keep him comfortable - trim according to what the hoof is asking for, NOT what someone thinks should be done to "correct" the horse.
There is no such thing as correcting a club hoof - as long as they are frequently trimmed (4 - 6 weeks, depending on growth rate), the hoof will be fine.
My 18 yr old TWH has a genetic less than grade one club hoof. He's been with me since he was 2-1/2 and has only worn shoes 5% of that time. He is fortunate to have hooves like goat and has been trail-ridden in some places my other TWH's could not go barefoot.
The few times I did have shoes on him, he wore the standard rim shoes with borium head nails, just like my other horses. Nothing special about the shoes -- just the proper size and properly formed for his hooves.
His running walk has always been nothing but champagne-smooth.
He's never been lame or sore but thrush has always been an on-going issue for him, especially in the club hoof because a club hoof isn't real good at self-cleaning.
Lastly, no matter where I've lived in this United States, I've had farriers or trimmers that recognized "trimming him to keep him comfortable" was the proper way to trim him.
There is a certain amount of math and physics that goes into balancing a horse like this. If your current farrier isn't comfortable with all that, please find someone that is before your horse ends up lame; something there is no need for, just because of a club hoof