I have the Amplified Bible which really makes IIPeter 2:20-22 sound the opposite of what you are arguing.
v20 For if, after they have escaped the pollutions of the world through [the full, personal] knowledge of our Lord and Savior Jesus Christ, they again become entangled in them and are overcome, their last condition is worse [for them] than the first.
v21 For never to have obtained a [full, personal] knowledge of the way of righteousness would have been better for them than, having obtained [such knowledge], to turn back from the holy commandment which was verbally delivered to them.
v22 There has befallen them the things spoken of in the true proverb, The dog turns back to his own vomit, adn , The sow is washed only to wallow again in the mire.