In Mark 7:3 there is a modifier, "πυγμῇ νίψωνται". "...unless they fist-wash their hands...". No one knows what the modifier "fist-wash" indicates. It could be washing "vigorously" or "using the fist" or something else to enhance cleanliness:
ΚΑΤΑ ΜΑΡΚΟΝ 7:3 Greek NT: Westcott and Hort / [NA27 and UBS4 variants]
οἱ γὰρ Φαρισαῖοι καὶ πάντες οἱ Ἰουδαῖοι ἐὰν μὴ πυγμῇ νίψωνται τὰς χεῖρας οὐκ ἐσθίουσιν, κρατοῦντες τὴν παράδοσιν τῶν πρεσβυτέρων,
In Luke 11:38 it appears that Jesus had decided to dispense with washing his hands at all before the meal presumably to "pick a fight" Samson style with his host. So the words "fist-wash" are not at all being used ceremonially as the focus was on some kind of "scrubbing".
Jesus tells them that what they need is to have their hands cleansed from [having shed] innocent blood.
So as I see it, in the Luke case Jesus had not washed at all but in the second, not to the measure of "fist-washing" as required by the oral tradition.
the washing in Mark simply a cleansing?