Even though the built in wall hack isn't that great there is a much better way if you enjoy camping. Hide behind any box and do the debug menu and select static props. Since counter-strike source only has one map (de_dust) all the boxes are memorized in everyone’s head. The static props removes all the boxes on your node allowing you to hide behind a box and still see what's on the other side. Quite fun for surprise attacks. The built in wall hack gives you this blurry effect which can be a bugger on the eyes.
If only these features were possible to bind to some keys the wall hack could be very useful. But pressing shift + f1 to disable and re-enable these built in ‘features’ does get bothersome.
-Girls have cooties! RUN!