I haven't tried but I believe that if one pricks the two ends of the egg then that leaves sufficient leeway for pressure to escape. On other things in microwaves, there's a UK TV programme called Brainiac which disposes of microwaves explosively on a regular basis using balloons filled with various gasses and a metal strip to get the spark going.

Over and above this, in the far distant past, the comedy duo Hale and Pace did a sketch involving a kitten in a microwave...
(Wibblist Last said "Wibble" on, Fri 5 Nov 2010, 11:18, 2 replies)

Thats amazing
Hale and Pace were comedy?
(andythepieman Is surfing the waves of indifference on, Fri 5 Nov 2010, 15:34, closed)

Alrite Craig

( Light In Chains maker of the ikea sofa, Sat 6 Nov 2010, 16:46, closed)