Draining the sink

After celebrating Christmas Eve, I was left with the task to do the dishes. And to make things difficult, the sink was clogged that whole day. I remembered 5 years ago when my dad asked me to buy liquid Sosa (sodium hydroxide) because our kitchen sink was clogged back then. He poured it on the clogged drain and all the stuff inside floats up to the surface, dissolving the gunk, which solved the problem. When I did that it didn't worked out like before. This time it is much worse. The chemical did not worked and I needed to fix it the hard way; drain the pipe myself. I unscrewed the cap beneath the sink, then all the nasty stuff came pouring down. It looked like chunks of slimy tofu. After that, the sink worked fine again. ~_~