Ditch the harsh chemicals and stick with the vinegar, you just did it wrong. The sticky mess is what happens when you don't wipe the wood down with plain water after, that's step one. Baking soda is for cleaning, not stripping, so of course you messed up by mixing them together. Old furniture like that has decades of grime and wax on top of the varnish, so the vinegar needs time to soak in, not just a quick swipe. Citrus strippers might be fast but they eat into the original patina and make the wood look all blotchy and fake. Patience is the real trick, let the vinegar sit for an hour and scrape gently, you'll get a way better finish that actually matches the piece's age. Chemical strippers are for people who want new-looking junk, not real restoration.