Elaina, Eventhough it's been AVAILABLE for a few years and I have a few Links on my HERBAL THERAPY Web-Pages (see below), I'm SORRY to say that I've NOT used Olive Leaf Extract, NOR have I studied it in ANY GREAT Detail.
You should NOT be concerned with Alcohol being used, because you're putting a VERY SMALL Amount into your Body. If you do have a PROBLEM, then put the Tincture in a Spoon and cook it, using a Lighter, until you see the Alcohol evaporate as a Vapor. By the way, Organic Alcohol is a SUPERIOR Solvent, dissolving MOST EVERY Constituent in MOST EVERY Herb. Organic Alcohol is also a SUPERIOR Natural Preservative, and Herbal Tinctures have been known to LAST over 100 years! Last of all, Organic Alcohol SPEEDS the Herbs, going into your Body, by bypassing the Digestive System, and passing VERY EFFICIENTLY through the Mucous Membranes in your Mouth.
Use Apple Cider Vinegar (preferably Bragg's - has Mother Culture) in the above SUPER TONIC or when making a Lobelia Tincture (1/2 vinegar + 1/2 alcohol). Lobelia contains 14 Alkaloids and some of them can ONLY be dissolved by Vinegar.
OH, and by the way, in case you might have assumed it, I'm NOT certified as a Master Herbalist. I've studied Herbal Therapy for over 40 years and have learned Herbal Healing Information, especially from Dr. Schulze , that I couldn't have gotten in an Herbal Therapy School or even in an Herbal Therapy Book today!
I HOPE that I've answered your Questions and CONCERNS. "THANKS" for your post!