The other day, we noticed that our bathroom sing was starting to back up when we would run the water. So, we dumped some drain-o down the sink and that did nothing. Because we live in such an old house with old pipes, we run into this problem a lot, so we pulled out the big guns: a product that clears the pipes with a huge burst of air pressure. I stood by nick's side as he covered the drain with the container and WHAMO!!!!!!
You know the hole near the top of the sink that prevents you from overfilling the sink? Yeah, we didn't think to cover that when we sent a shock-wave of air through the pipes. Our bad, heh heh.