If you can make some connections at your local track, it's not hard to find out who is getting rid of what.

I think a lot of times the "MUST BE GONE BY TOMORROW!" is more of getting the horse out of the barn to bring in another potential winner than "must be gone or goes to slaughter".

I missed out on a very nice grey gelding with a bone chip. He got the surgery to remove it and is in retraining now for Hunters, I believe.
I also missed out on a very nice bay mare who didn't like to run. She's a polo pony now.

I'm pretty close to Sam Houston. Most of the trainers/owners who have horses there are good at sending out the call to rehome and most of the horses have new homes within days if not hours. If you want one, you have to act fast! I know there are a couple of excercise riders who will take them and retrain/rehab them and then sell them for a nifty profit. A lot of them are really nicely built horses that just don't have what it takes to be a racehorse.

A woman is closest to being naked when she is well dressed. -- Coco Chanel