Cleaning microwave after incineration of food

[MEMsmum]

DH cooks dinner on Thursday evenings and last week's piece de resistance was baked potatoes. Thursday evenings are very busy in the MEMs household so he popped DS's potato in the microwave (was going to finish it off in the oven to "crisp" it up) and went off to collect cats from the vets. They came came back 20 mins later to a house filled with smoke! He'd only gone and nuked them for 20 minutes!!! We're lucky the house didn't burn down - and rather worryingly the smoke alarms which usually go off when we're using the top oven didn't utter a peep!! Eek!! Potato was a carbon shell which collapsed on contact. Microwave is now stained with lovely brown smoke stains - he's scrubbed, I've scrubbed, we've done the lemon in water bit but no joy - still covered in brown stains. Can any one help? Or am I fated to another 6 month search for a microwave I actually like?

Oh dear.

Have you tried using steam? Either with a cleaner or by putting a half filled bowl of water in and cooking it for 2 - 3 minutes so that steam is created.

Can't think of anything else. Jif? Bicarb of soda paste?

Thanks Deux - have already tried the steaming route; it's just made the kitchen smell (and kids now saying they can't possibly go in to help themselves to water as it makes them gag !!). Will try the bicarb route next - worked on the vomit patches DS distributed around his room at 3am on Friday night! Good old mumsnet - always there to to rescue!!