How do you say 'detergent'?

I needed some liquid detergent to rinse out my clothes in the hotel sink. Problem was, I didn't know the Chinese word for detergent and had forgotten to ask anyone at the office. What's a foreigner to do?

I did the same thing a Japanese student of mine once did when he was looking for an implement to unstop a toilet-- I wandered around a supermarket. My former student knew much more English than I knew Chinese. A doctor and medical researcher, he knew words like 'cardiovascular' and 'hypertension.' But he didn't know the word 'plunger,' anymore than I know how to say 'detergent' in Chinese.

Now, by American standards, a Chinese supermarket isn't that big. It's more of a mini-mart--even smaller than the A & P my mother went to back in the 50's. Still, things take longer when you don't know what you're doing. It took the better part of an hour to find a bottle of detergent.