Once you have bought a new can of deodorant to replace that which was confiscated on an earlier metro journey you may again face ejection from a station when your bag is scanned. If this happens cross over the road to the other metro entrance where the security people will not recognise you, place the offending item in your pocket, and walk through security with a big smile on your face.
We’re not sure the same techniques will work in Tiananmen Square though, caution is advised for future travellers!
Laura