Drives me nuts too.

I hadn't found this sticky, but found one on google search for Chrysler 300 and worked the same. I didn't need to start the car to do this.

I just got in the car.
Buckled the seat belt.
Turn engine to ON without starting. (Waited long enough here to no longer hear initial chimes as I recall.)
Released and buckled 3 times.
Turned engine off, heard the confirmation chime, unbuckled and it was done.

These instructions are here. http://www.justanswer.com/chrysler/6...t-warning.html