Yeah, definitly charge through your own men if its needed and don't forget to use rally. But don't just stop there, with decently armored cavalry you can charge right through the enemy unit too, then swing around and hit them from behind. Thats what I do when in cramped quarters, you can even use it on the opening part of the battle. Sending your cavalry crashing through their lines with your infantry just behind. Their formation will be disorganized and its even possible they will turn to try and chase your cavalry, exposing their rear/flanks to your infantry.