I tried Pitchblend once. Never seemed to soak in and was always sticky.
I am a huge fan of Obenauf's dressing. NO OIL !! Beewax and propolis.
I believe that neatsfoot, mink, tallow or any other oil will eventually rot leather.
Here's a test for anything you are going to treat a glove with. Dip your finger in it and take a big taste. If it is safe for you, your bird should be okay eating off of it.
I actually do use this--the leather dressing, which is heavier wax-based, more than the oil. It is a bit tougher to get to soak in, but the microwave trick usually does it. You have to work the leather more but once its in, I find I don't have to re-treat it as often. I'm also a MT girl, so I'm a little biased :-p
If you dislike someone, walk a mile in their shoes. Then, you are a mile away from them, and you have their shoes. --Jack Handy
I rub a dose of Obenauf's dressiing on my glove or new jesses and hit 'em with my wife's hair dryer. Watch it disappear right into the leather. Not too hot !