Those who insist baptizo *means* to immerse ought to consult a lexicon.
4 καὶ ἀπʼ ἀγορᾶς ⸆ ἐὰν μὴ* ⸀βαπτίσωνται οὐκ ἐσθίουσιν, καὶ ἄλλα πολλά ἐστιν ἃ παρέλαβον κρατεῖν, βαπτισμοὺς ποτηρίων καὶ ξεστῶν καὶ χαλκίων ⸋[καὶ κλινῶν]⸌*
Aland, K., Aland, B., Karavidopoulos, J., Martini, C. M., & Metzger, B. M. (2012). Novum Testamentum Graece (28th Edition, Mk 7:4). Stuttgart: Deutsche Bibelgesellschaft.
The Jews did not *immerse* their couches and yet the word βαπτίσωνται is used for ceremonial cleansing throughout the Septuagint.