I called 20 offices and got 3 offers to shadow. It's especially easy if you went to an undergrad that also has a medical school. They probably have a clinic and, even if it's an MD school, most likely have at least a handful of DOs working there.
Just call and say "I am a xyz university alumn and am interested in shadowing dr. so and so." They'll ask you what you intend to get out of it or why you are doing it and you just say "I am applying to medical school this year and would like to gain some exposure to the osteopathic principles and practices. I have shadowed in the past and am familiar with hipaa and the importance of patient safety and privacy."
Some will tell you (most likely BS) that they can't let you shadow because of hipaa or hospital policy or whatever. Others will flat out tell you no, and others will say they'll get back to you without any intention of doing such a thing. If they say no, just thank them and move on. You never know when you'll encounter some of these people again. Chances are they won't remember your name, but better safe than sorry.