“6) Wash for a davar shetivulo b’mashkeh
Also explicit Halachah, and one which (by fruits) the Shulchan Aruch (and Gemara) say that one who follows is arrogant.”
In context, (O.C. 158:5 and M.B. 158:2, 158:22) it seems to only be referring to fruits which are not dipped in liquid. You made reference to a gemara. Where is it?