Not strictly boat related, but people have been known to sew on boats..... Iím re finishing a few sewing machine treadle cabinets, which have the usual assortment of damaged peeling varnish, dings and dark stains, presumably from water seeping through from cups plant pots etc. I scraped back the top on one last night and interestingly one dark stain seems to be more prominent in the morning.... Anyway, there seems to be lots of suggestions for removing dark stains, ranging from toothpaste, mayonnaise (not kidding), olive oil, bleach and Ajax powder to oxalis acid at the more extreme end. What Iím after is to remove the dark stains and perhaps lighten the wood (veneer) a bit before re varnishing. Any simple foolproof methods out there?