Slightly different, but I spotted an ad on our local ads site looking for somebody to keep their horse for several months until the rider was back from injury, had more money and had more time....
Either lease the horse or sell it, don't expect somebody to take care of for you for free.
I also see plenty of ads of horses for lease, green horses requiring experienced rider.... so you want somebody to pay you for them to train it?
Stop for a minute, open your mind, learn. You may not agree with what I say, I may not agree with what you say but we will both learn something new.