You can also mix and taste immediately with vodka. With zest you must wait for the flavor to diffuse.
A vodka tincture is not not necessary. I add fruit and spices to many ales and most all brett beers and do not sanitize any of it. I have never needed the extra extraction vodka would provide. I learned the zest thing from my wife. She has been using a micro plane to zest fruit and add it to 2 quarts of water in a pitcher. It's a great flavored drink. I micro plane the zest, Starsan my hands and a fine mesh bag, secure zest inside bag and through it in at kegging. A little zest and an IPA or APA is mighty tasty IMO. Oh, a micro plane eliminates the pith, you do not want that in anything.
I don't suggest to add the zest to voka for sanitation but for flavor extraction. Seems to work better than just adding directly to wort plus, more importantly, you can add a bit at a time until you get the flavor where you want it. If you add too much zest you can't take it away.
Then there's that!
Vote Jonathan Fuller for Governing Committee!