I tried to make some with the blue can and I was able to get them out by pushing a marker through the bottom of the pvc. The only proplem is that there are air bubbles in the middle of the dart... great great texture other than that, though!
Great Stuff seals itself up after about two hours of no usage. So this would be a one shot deal. Also the blue can dries flexible, where as the red and black cans dry rigid.
I think I've said this before, but I work at ACE Hardware and we sell this stuff. It comes in three sizes, blue-small holes(for around windows and doors), red-medium, black-large gaps and big holes. Holla!