For lack of time, I submit the following from another source:
"But immersion is not the only meaning of
baptizo [in Greek]. Sometimes it just means washing up. Thus Luke 11:38 reports that, when Jesus ate at a Pharisees house, "[t]he Pharisee was astonished to see that he did not first wash [
baptizo] before dinner." They did not practice immersion before dinner, but, according to Mark, the Pharisees "do not eat unless they wash [
nipto] their hands, observing the tradition of the elders; and when they come from the market place, they do not eat unless they wash themselves [
baptizo]" (Mark 7:34a, emphasis added). So
baptizo can mean cleansing or ritual washing as well as immersion."
http://www.catholic.com/library/Baptism_Immersion_Only.asp