HELP! My tub and bathroom sink drains are very slow, if not clogged. I have tried Liquid Plummer, Drano, and white vinegar/baking soda. I was able to clear out my tub drain with the white vinegar/baking soda trick, but the bathroom sink will not even drain the vinegar. My kitchen sinks drain just fine, so I don’t think it’s a sewer main issue. My friend says I should try muraic acid on the bathroom sink, but I am worried I’ll damage the pipes. Aside from calling a professional on Christmas Eve day (I am having company for the holidays), what should I do?