It is clear from the context...
"I thank God that I baptized none of you except Crispus and Gaius, so that no one may say that you were baptized in my name. (I did baptize also the household of Stephanas. Beyond that, I do not know whether I baptized anyone else.)
... that Paul wasn't too concerned terribly about baptism.
This is exceedingly difficult to reconcile with your believe that baptism IS salvation.
The water of baptism isn't magical. Baptism is not salvation. It is the outward sign of a repentance and turning from sin that has taken place IN THE HEART. If that hasn't happened, then no salvation has happened - no matter how much water you put on your head.
Would you believe it if Peter himself told you?
I never once said that Baptism is salvation, I said, and quoted Jesus, that it is a necessary requirement for salvation. IOW, as Jesus said, without it, no one gets to heaven.