PTŠab 10.b:1[2] :מנערה שרי וממחקה אסור‏ : (if water fell on his garment on the Sabbath) it is permitted to shake it off, but forbidden to rub it off
See the entire entry for mḥq vb. to wipe out

PTŠab 10.b:1[2] :מנערה שרי‏ : it is permitted to shake out
See the entire entry for nˁr vb. D to shake out