R.M.
I shop at consignment sales all the time, and always wash everything meticulously that I buy used. (probably too meticulously). I wash everything in the washer or dishwasher on hot. If it doesn't make it, oh well, I wouldn't have used it anyway. I don't buy things that look like they could be safety issues, so I wouldn't keep those things.
But never throw things out, always donate to goodwill or a shelter. If something is not sell-able, let them decide to toss it. (Again, unless you know it isn't safe.) With the economy the way it is, it is such a shame to throw out things that you don't want or like, because there is always someone who might. Even dirty stained stuff. My husband needs jeans for his job that get absolutely ruined in the first day. I always buy the most ruined jeans off the goodwill rack. I can't afford to buy him new just to get ruined, and if people donate the stained, ripped ones, I dont have to buy the ones in decent shape and can leave those for someone else who needs them.