This takes me back to my childhood. It is one of many nonsense songs sung by my mother and others in the family,including me eventually. We sang it thus........
You push the damper in, and you pull the damper out
And the smoke goes up the chimney just the same.
You push the damper in, and you pull the damper out
And the smoke goes up the chimney just the same.

    Chorus;- We were only playing leap frog
             We were only playibg leap frog
             We were only playing leap frog
             When one grasshopper grasshopped across another
             grasshoppers back.

That's all there was to it, you just sang on ad infinitum until you got fed up.   The movements were the obvious push forwards and pull back, then on 'smoke' point the index finger upwards and raise the arm with a spiralling motion to mimic rising smoke.