ῥυπτήρ

From LSJ

ἢ δεῖ σιωπᾶν ἢ λέγειν τὰ καίρια → you should either keep silence or make timely remarks (Menander)

Source

German (Pape)

[Seite 852] ῆρος, ὁ, der von Schmutz reinigt, der Wäscher, Diosc.