Our experience is that it did have a short shelf life and developed a quick sharp vinegar bite as it aged. We made it 10 gram batches that when split amongst students or ourselves didn’t last long enough to see how it would do long term.
I kept mine in a closed 2 dram balm jar, but made no attempts to use a desiccant or exclude atmospheric moisture, which I later learned was probably the culprit.
Perhaps dissolving it in a hydrophobic medium might slow that down.