How should I clean a Kartell FLY light?

[aftereight]

This:
m.johnlewis.com/mt/www.johnlewis.com/177069/Product.aspx
Mine is dusty, so have tried dusting it, but kitchen dust seems to be a bit more sticky than normal dust.. Can't take the shade off, so any ideas how to clean it without scratching it or smearing it please? Smears would be VERY obvious.

m.johnlewis.com/mt/www.johnlewis.com/177069/Product.aspx
Link, hopefully!

If it is in the kitchen the stickyness is cooking vapours. I dont think I would dare to use bicarbonate of soda on it for fear of scratching it so i think i would try with a soft cloth with warm soapy water ( washing up liquid).

Thanks, will give that a try, and use an ecloth to try to de-smear afterwards.