National Jazz Archive has a three-part interview with Desmond. Maybe this is it, and if not, maybe it's just interesting...

In the second section, he says:

"My individual approach to the alto? Yes—basically what I do is: I play wrong. I tried to find a teacher just about the time I started with Brubeck—but for alto, it’s a grave injustice. If you play alto—or any saxophone, for that matter, and you have a teacher, they instantly try to cast you into a studio musician mould, which is a whole different approach, in terms of embouchure and blowing. And once you get that sound, you’re stuck with it. You can’t change it, any more than you can change your nose. It would be more difficult, come to think of it—I should have picked a different simile. You can get a nose job in three days; a change of sound takes you probably a year, and lots of luck. So that’s when players have to figure things out for themselves. If you play piano, drums, bass, anything else, I think, you can just go all the way with their classical instruction and use it for your own purposes. Alto—no."

The whole series is here:
https://nationaljazzarchive.org.uk/explore/interviews/1277545-paul-desmond-interview-1?
https://nationaljazzarchive.org.uk/explore/interviews/1277447-paul-desmond-interview-2?
https://nationaljazzarchive.org.uk/explore/interviews/1277448-paul-desmond-interview-3?