I don't know. Probably every school does something different. But they definitely see the old scores. I can see them myself when I log in to the MCAT website and also on my AMCAS. None of my interviewers ever brought up the old scores except in the context of wanting to know how I did so much better the second time. (My first score was nine points lower.) I'd guess that if the scores are old enough, and you did well on the test recently, the old scores probably won't hurt you that much. But the OP was talking April to August, so those first scores are still going to count at some schools.
Moch, even if you do that, the schools will still know that you attempted the test. The AAMC will put the attempt on your record. There isn't any loophole, unfortunately.
One other.thing to keep in mind is that once you've taken the test three times, you have to get their permission to take it again a fourth time. To do this, you have to promise that you're taking it for medical school admissions purposes and show them something like a rejection letter so that they know you're really applying. I've never heard of anyone being denied permission for a fourth take, but it could still be a hassle.