On Sat, 23 Apr 2005 14:25:28 +0100, Owain
wrote:

When you flush the toilet, aerosolised fecal matter laden with bacteria
is sprayed into the air. It is this which you need to extract to the
outside, rather than 'odour' per se.

Didn't your mum teach you to shut the toilet lid before flushing? ))

cheers,
Pete.