Here are some links to Patsie Thompson's (sp?) method of spray basting. The first link has some info at the end of the vidio then she answers more questions in the second vidio.
http://www.youtube.com/watch?v=39I5A...eature=related
http://www.youtube.com/watch?v=nwV8tUkhxUM
I use this method all of the time. I hope this helps!