carb adjustment

hi folks
I have a holley 750 on my magnum 360 that just fouls out the plugs and runs terrible. if I turn the air/fuel mixture screws in all the way it smooths out. I didn't put a vacumm gauge on it to see my readings yet. I don't drive the car much so if its dirty could I just remove the screws and squirt some carb cleaner in the adjustment holes?