I know in a lot of areas where mountain bikers have to deal with thorns, people will put this green slime into their tubes/tires to help seal small leaks. I know I got a container of it a while back when I did a race in AZ, but since it's not really needed in MN I think I chucked it. My guess is that if they have lots of thorns in the area, a few local bike shops would have that slime stuff....
I've never tried it, maybe I'll give it shot one of these days. The tires I have on both my commuter and road bike were purchased last year on various recommendations from the local bike shops as being pretty good with the thorns, but I haven't been overly impressed as of yet. You got to see these thorns, they'll tear your face off if you give them a chance.