I used to. Have since upgraded. I used both a double drilled stopper and a carboy cap (not at the same time, but both work). I used the 3 piece airlock (as opposed to the "S" shaped one). You can slip a blowoff tube over the small tube of the airlock (I had a broken one that I cut the outer shell off of to make it smaller, but this isn't necessary). If the thermowell is pushed in deep enough there is no interference.