If it bothers you, yet you don't want to use chemicals to get rid of them, nor want to spend your entire Saturday afternoon picking and digging with something pointed to loosen them from the cracks, I have the answer for you.
Very simple. . .
Boil a teapot of water and pour the boiling water right on the weeds. Within 24 hours, they'll be dead and ready to pick up. NO muss NO fuss . . . and earth friendly. And you'll have hours to enjoy the beautiful summer weather another way!