Thrush treatment and preventation

We are battling thrush and to help with this the horses feet need to be kept drier. Not easy when they are out 24/7. But I wonder if they read my mind or if they are instinctively helping themselves? After breakfast they all took a turn hanging out in the field shelter which has a dry floor.

Ideally I'd like to create an area of pea gravel or at worst road scalpings where I could keep them for a couple of hours at least every day. I will have to negotiate with the landlord and see what can be done.

In the meantime we may have to keep the horses in the field shelter/stable overnight which is not ideal as it goes against the principal of allowing them free movement 24/7.

Each horse is having its feet picked and treated twice daily. The US preferred treatment of Lysol is not available in the UK. We are starting out with a salt water wash and packing the feet with cotton wool mashed in heel to hoof. If this doesn't provide quick relief we will try something else.