it's a bit of a bugger you can only do it with tele style single coils and MQs. It's got to be possible to get hold of a metal soapbar casing...
there is a chrome soapbar cover, matt bellamy has it on one of his guitars
The standard chrome P90 cover wont work - its plastic underneath - will melt
I have tried heating chrome up with a blow torch - wont work 
Well i originally asked Tim bout it and he said that its impossible, But me being deluded that i can go against the laws of physics, gave it a go.
its a regular chrome cover, and although it had wax on the inside that exploded, it still worked and it was very plasticy before hand (sp?).
My advice is to give it a go and see, maybe if you heat it slowly it will give a different effect to heating it fast i dont know but dont stick with theoretical knowlege. Remember in theory hand wound pickups shouldn't sound better then precision machine ones! but they do!
