My colt was older but that was because I didn't trust the vet I had when I first got him. My vet now will do them whenever she can find both of them, anywhere from 2 months on (she doesn't like sedating the little ones younger than that.
I'm not sure what your riding instructor meant by "a lot of work" though. Recovery only took about a week, and all I had to do was make sure he got his antibiotics and work him every day (which I did anyway). Some vets recommends cold hosing afterwards, mine said to cold hose if he had a lot of drainage or swelling, but otherwise with the antibiotics he should be fine. At most even if I had been cold hosing daily it would have been an extra 10 or 15 minutes a day for a week or so. Really not much work at all. And mine is certainly much happier now than he was before.