This comment/reply is prefaced with an apology for being a downer.
Personally, I would not talk about a low MCAT score unless something tragic happened during your exam (in which case you should retake). There are an enormous number of applicants who feel the same as you about their experience, even the ones who scored well. I don't think the ad com would view your situation as extraordinary or poignant, which is the only capacity in which I would mention an MCAT score. (I would certainly not bring up practice scores at any cost -- meaningless to the ad com.) Even more to the point, the MCAT tests your ability under pressure. I'm not sure you want to go out of your way to tell ad coms that you struggled under pressure. Med school, residency, and your career will have tremendous pressure at times, so you need to paint a picture of resiliency!
Gotta own that MCAT or get a better score. I think those are really the only two options.
Best of luck!!!