Okay......... so it's been a busy few weeks. Allow me to update:
The Leather Sheen comes in a spray paint like can and makes the deglazer smell like a bouquet of fresh roses. I gave the bag a few thin coats, allowing it to dry and fully buffing with a cloth between coats. After about three coats, it seemed impermeable to water and showed virtually no color transfer but it was all stiff and shiny, with this weird sticky feel. I brushed the whole thing multiple times with the horsehair brush, hoping to dull the finish and remove some of the sticky residue, to no avail.
My dad, being old school, suggested saddle soap. At this point, I'm up for anything. I've been over it multiple times with saddle soap, brushing it vigorously each time. It looks better and better after each round -- I even wore it out of town this week -- but it's still a little shiny. I'm going to keep at it and will let you know how it goes.
As an aside, while researching the whole leather dyeing topic, I found a technique called "vinegaroon" which sounds fascinating. It would require complete removal of all the sealant but I wish I'd heard about it before I started this project -- I would have totally been game to try.
http://www.adamsleatherworks.com/vinegaroon-a-k-a-vinegar-black/
