I don't THINK you can go straight from AC to a clearinghouse. It certainly cannot accept the remittances to let you know what cleared and what did not, and that is important.
How are you generating 5010 files? When I go to export, I get:
Now I know the options change based on the billing service (and this was set to my prior service (working from a backup), but I don't see a way to do 5010's