You could also take a regular paint brush and paint a little in between the boards. (carriethishome.com)
I went with a regular paint brush for painting, an Annie Sloan wax brush for the dark wax, and just rags for applying the clear wax. (funhomethings.com)
I painted the dresser using 2 coats of homemade chalk paint with a regular paint brush and foam roller. (loveyourabode.com)