Without doing scripting I don't think you'll be able to automatically disconnect a call after 1 minute.
You can clear it manually with this command:
nicmatth-sip#clear call voice cause 16 id ?
<1-FFFF> call identifier as shown in brief format
Use 'show call active voice brief' to get the call id.
You could incorporate this into a router kron job with a script if you got fancy.
hth,
nick