The word is in quotes because I'm referring to the Greek word βαπτίζω, not the English word “baptize”.

I just noticed that in Josephus, Vita §15, the word βαπτίζω is used. Here's the Whiston translation:

for, as our ship was drowned in the Adriatic Sea, we that were in it, being about six hundred in number, swam for our lives all the night; when, upon the first appearance of the day, and upon our sight of a ship of Cyrene, I and some others, eighty in all, by God’s providence, prevented the rest, and were taken up into the other ship:

The italic is the instance of βαπτισθέντος, an aorist passive participle. Intrigued, I thought I'd search the NT for use of the same exact inflected form. I found one hit, in Lu 9.21:

Now when all the people were baptized, and when Jesus also had been baptized and was praying, the heavens were opened,

Now, please don't read too much into this. The contexts are completely different; you can't read this as “whoa, Jesus was dunked, not sprinkled! Just like the boat in Josephus!” Why? Well, the ship was destroyed as a result of its “baptizing”. You wouldn't want to apply that little bit of inferred meaning to Jesus, would you? (If you would, we need to talk. Seriously.)

Still, it is always of interest (at least to me) to see how the same word is used in secular context vs. religious context.

Ok, back to work, people.