As Rachel welcomed strangers at the well with water, so do we welcome each other to this Seder by washing the hands of thos at our table.  We are not washing ourselves of dirt, but of attachment, guilt, and resentment. Each person in turn pours a little water over the hands of the person to the left, into the bowl.  As the water is poured, think of something that you wish to let go of and imagine the water carrying it away. 

haggadah Section: Cover
Source: The Buddhist & Jewish Haggadah