Sorry, but I know of no way to exclude P&N posts from any forum search. I'm personally sympathetic to your plight, though.
“I had the idea to draw Muhammad because [...] we are above all cartoonists who love to draw little guys, like when we were children. The terrorists have been children, too. They drew like all the children do, and then they lost their sense of humor.”
-- Renald Luzier, who late for work on the day of the massacre at Charlie Ebdo