You can also probably get the right size hose and stick it through the stopper. Only my second batch but I'm glad I went with a blow off tube this time.
black imperial ipa by Glamisduner, on Flickr
I filled the growler(1/2 gallon carboy) about 1/3 full of starsan solution. Event though I have emptied it 3 times now It still filled up and overflowed twice, gotta clean up the freezer once it settles down a bit more.
Lots of hops shooting out the top into the growler, it smells great when I dump it down the drain, but also makes me sad.