why dont you use 2 blowoff tubes? Homedepot or lowes sells tubing if you just dont have any...You can hook it through the carboy cap or take the bell portion off of a 3 peice airlock and put a tube over that. How many days have you been fermenting? If you add ice it will slow things down but 67 degrees is a pretty decent temperature. I would go the blowoff route.
On Hiatus: Brewing at work....