Are these people truly so clueless that they don't see how inappropriate this is? Is this not what a vet, farrier or trainer are for? And quite frankly if they are not willing to spend the money to have their horse evaluated by the appropriate professional then I wonder why on earth they even have the horse in the first place. Horses by nature are not cheap creatures to maintain.
Today I read just such an ad on Kijiji and my advice was for them to call a vet. For crying out loud - it sounded like the horse had foundered, and this my friends is how horses end up as dog food. Grrrr!