[Not just another dumb blonde]

Wouldn’t the flood water be considered purification, in the sense that God had to pass judgement against man for his wickedness? And if that’s the case, it’s a judgement, not a baptism?

But what you’re supposing in Ezekiel is not baptism, but a cleansing, changing their hearts.

[annalex]

St. Peter discusses the flood being a type of baptism in 1 Peter 3:

20 [The ancient Hebrews] had been some time incredulous, when they waited for the patience of God in the days of Noe, when the ark was a building: wherein a few, that is, eight souls, were saved by water. 21 Whereunto baptism being of the like form, now saveth you also: not the putting away of the filth of the flesh, but the examination of a good conscience towards God by the resurrection of Jesus Christ. 22 Who is on the right hand of God, swallowing down death, that we might be made heirs of life everlasting: being gone into heaven, the angels and powers and virtues being made subject to him.

As you can see, I didn't invent it.

what you’re supposing in Ezekiel is not baptism, but a cleansing, changing their hearts

But that is what baptism does as well: it gives a new birth.