In retrospect, I feel pretty stupid about leaving the mug closed to begin with. I should have known that pressure would build. And besides, there was no practical need to leave the mug sealed- I sealed it when I shook it, and just left it that way. Dumb…but there you go.

That said, I’m happy with how good of a job the process did with cleaning the coffee stains. It was very effective, and avoided abrasive scrubbing which is something you aren’t really supposed to do on polished stainless steel. And I’m also impressed that the “explosion” seems to have done no lasting harm to the mug. The lid portion was blown cleanly off without breaking, and just snapped back into place- the downside there is that I put it back on before realizing there was still a silicone seal ring lying elsewhere in the kitchen.

Regarding the cats…you know, I’m not sure where they were throughout this process. I suspect they were upstairs with Irene- although usually Iris is poking around getting into trouble downstairs until just after I go to sleep. She seems undisturbed this morning, so either she was nowhere near the cup when it exploded, or it didn’t bug her very much.