Whenever I've done test installs with our product I've always used silicone spray and a plastic weatherstrip stick.
http://precisionrestorationparts.com.../F32237082.jpg
The stick helps work in the rubber without piercing it.
By the way, the post seal rivets on the division bar and the main seal presses into the channel. There should be no reason to use weatherstrip glue on any of this weatherstrip.
-d