that just means that when you handle it
you do it with thumbs outwards and your face twisted round in an apprehensive grimace, in case it goes off in your face.
(
Grrrmachine the indifference engine, Mon 1 Jun 2009, 19:56,
archived)
That'd be great rhyming slang.
"Cor, look at the sulphurs on her!"
(
Druid, Mon 1 Jun 2009, 20:05,
archived)