Separate bowl for me.
I too for about 40 years use to whip up my lather in the soap mug. When I saw 'You Tube' videos with guys using a separate lather bowl to make lather, at first I thought, how silly. But then I tried it. No going back now.
Sorry to go off topic, but you need an orange brush in a parka and your avatar will be complete.
Who knew...been using the same bowl all these years. Maybe that is why my soap doesn't last as long as some I have seen.