I use a squirt of ecover washing up liquid and another of ecover dishwasher rinse aid. These came with my tumbler and I never had cause to change. Seems to clean even black powder staining.
I was struggling to register on another site many years ago as my then favourite moniker was gone. The first thing I saw when i looked up was the words "fire exit" on the wall opposite my desk.
Kinda stuck
Chris