A very good idea, but my advice is to have some strict filters for elimination.

E.G. if the horse is beaten by more than 3 lengths at any start discard it.

Just a rough example...otherwise you'll be following horses which cost you bet after bet.

I would wait until the horse wins and then follow it for three starts backing eachway unless it has a very good first up record.

I would also look at the type of horses sprinters, middle distance, long distance and concentrate on one type.

It has merit if you're prepared to follow the good and throw out the bad and replace with something else very quickly, otherwise you'll just be hoping to fluke a win at bolters odds.