Hi,
I would not use a Debug for that. You may always use the "log" option in the ACL to see if the router is dropping any traffic. It will tell you the protocol, if it´s an extended ACL, source IP and destination IP addresses. Also the source MAC address, if you use the "log-input" option.
Another way to see if there are drops, is with the output of show ip traffic.
I would leave the "heavy artillery" for more complex problems or if you are not able to solve this issue with the other less intensive methods.
Hope this helps,
Jose.