Solvent 17 is not exactly exotic, but is a great stripper nonetheless. But there's still something on these spindles that it just wouldn't dissolve. Whatever those spots are made of it's hard stuff that I had to scrape and chip off with my scrappers. Then follow up with more scrubbing with the wire brush. I wouldn't be as worried about the appearance if it was not visible, but this is on a stair case and so it's visible as one looks up into the staircase.