So, half the people say it works the other half do not. I ran it through the S3D simulator to see where my print went wrong and layer by layer the 2 chambers simply do not connect. So either S3D is misinterpreting the STL or it's just a bad model.
If yours does not work, check the comparison of the simulator vs the cross section pictured above. It looks like maybe the shell is too thick and closing off the chambers when it's being printed.