I'd asked this question on APUG about heating new paper to age it synthetically and got a lot of responses but evidently nobody had tried it.
Sooo I finally got the chance to give it a go...

The picture on the right was"cooked" and appears to be lower in contrast and lost some speed also.Both were cut from the same sheet of Ilford Multi-Grade glossy paper,pre-flashed for 12 seconds and exposed in-camera using a 180 mm lens at f 8 for one second,then developed in Dektol 8:1 for 4 minutes. The cooking consists of sealing the paper in a can and"cooking" it in a toaster oven at 90 degrees for two hours. The first attempt was "cooked" for one hour at 250 degrees(forgot gelatin melts at about 97 degrees)needless to say wasn't successful.
I'm having a blast learning to use in-camera paper negatives.
Let me know what you think....
Don