That would hardly be in keeping with the clean-guy image of Mr Ma, a Harvard-trained lawyer.

ECONOMIST: Banyan

But Smith believes Rangers have given themselves a huge opportunity to win the semi-final tie by keeping a clean sheet on home soil.

BBC: Smith confident of Gers progress

Brand-rash is caused by not keeping the basic brand attributes clean and fresh.

FORBES: Does Your Brand Have Diaper Rash?

The Brazilian shot-stopper has become a cult hero at Ashton Gate, keeping 15 clean sheets so far this season.

BBC: Basso is City player of the year

The benefits of non-stick gum are obvious for government authorities, which spend a lot of time and money keeping streets clean.

FORBES: Magazine Article