Adam Clarke on Titus 1:11

Whose mouths must be stopped - Unmask them at once; exhibit them to the people; make manifest their ignorance and hypocrisy; and let them be confounded before the people whom they are endeavoring to seduce.

Subvert whole houses - Turn whole Christian families from the faith, attributing to the broad way what belongs only to the strait gate; ministering to disorderly passions, and promising salvation to their proselytes, though not saved from their sins.