Surprise series: Washing up

I was grossed out the first time I had Chinese friends over when I started living in China. They said they would wash up the dishes after dinner. But all they did was run them under some cold water. I couldn't believe they put them away with out washing them properly first. I had only ever washed up in a sink of hot soapy water.
Last year when I went to visit my parents I surprised myself. I was grossed out by the fact that they washed up in stagnant water. I guess I'm used to using running water now.