I made a hole in the side of my house to install a dryer vent. I want
to seal around it with the spray expanding foam insulation. Looking
at the Great Stuff brand, I can either buy stuff that cures rigid or
flexible. Here are links for both (rigid first):

http://building.dow.com/na/en/produc...gapscracks.htm

http://building.dow.com/na/en/produc...windowdoor.htm

Which one would be better? And it says on the can that it is designed
for one use, rather than using it a bit and saving it for a future
use, because the dispenser gets filled and cures. Is there any way to
save it for a future use?

thanks in advance,
John