This “mug” had a defect so being the DIY type I took my ceramic rotary bit and opened up the filled area, this unfortunately broke the mouthpiece and though it was a clean break, I used gorilla glue to put it back on, the clamps slipped loose and as the glue expanded the mouthpiece slid up. Now I was thinking if I can get some water in there and freeze it I could possibly pop it off but that seems unlikely and a hassle, so I thought I could possibly see if anyone who ceramics might have any input here