Last year they went to Edinburgh where a reviewer described them as "clever rather than funny." "If only they'd said that about me at school," Magenis laments, "I'd be head of ICI by now."
Their act is a lot smoother these days as they perform, without notes, 40 minutes of double-act Knowledge. According to Magenis, their subject-matter "starts off with the Big Bang and ends up with the enigma that is cling-film''.
In between they range over "the arts and crafts of Belgium and the history of erogenous zones. We used to do a section about John Major, because we're both from Brixton, but he probably won't be around much longer so we might drop that".
At their Purcell Room shows this week, the audience is invited to bring along their hideous unwanted Christmas presents to be donated to a deserving cause. "We've selected Terence Conran, because he has nothing tasteless," Magenis can exclusively reveal.They have already collected a tropical-fish-shaped bowl and a video starring Fergie.
The Men Who Know (and guests) are appearing at the Purcell Room at the South Bank (071-928 8800) tonight and tomorrow at 7.30pm