Thanks for the advice everyone, definitely the mica was the main source of flaking, some of it got really scorched somehow. I have managed to scour away most of the offending parts with magic eraser and managed to get the bowl almost perfect and golden again too.
Magic eraser really is the way to clean the vapman! Iso and cotton buds is useless on this guy lol
My bowl is getting pretty amazing looking after a thorough 20 min clean with magic eraser. A few more runs over with magic eraser, then i'll wipe the bowl down with wet cotton cloth, then dry off, torch, iso wipe to ensure any last nastiness is removed, then cook it off and reload for the next go!
Now to see if I can keep this clean if I give it a good wipe down in between loads of hash?