Two ways- 1, modify the internal power supply circuit (which uses a big capacitor and a few other bits, probably a Zener diode or 2 to drop the voltage), but this requires good working knowledge of transformerless power supplies, is risky and potentially expensive if you make a mistake.
2, use a small plug-in 220-110v step down transformer. They shouldn`t be too hard to find in your equivalent of Radio Shack or Maplin Electronics.
Thing is, I don`t think the mains powered Sauce stuff is designed to run from a 50Hz supply as we get in Europe. In the US, they have 110v 60Hz and to get this from 220v 50Hz would require a load of complicated or expensive equipment.
I had a Sauce Lightwasher plugged into my 110v/50Hz supply (I mainly use to power some of my xmas lights and a US-origin neon display voltmeter), and the silly thing died after about a month. Not sure of the exact cause of death as I havn`t "post mortemed" it yet. It
could have been due to a big nasty spike in the mains supply when I hooked up a bad 3KVA transformer and it blew out the power, cos it wasn`t long after this that I noticed it`d quit working. Those big huge transformers can give quite a kick when they feel like it...
If you want to risk it, get a 220-110 converter transformer and try it- the smallest 15-20va ones would be more than enough to run a Lightwasher, and hopefully you`ll have better luck than I did!
Our resident Sauce insider is mr Craig Johnson- Craig, have you heard anything from them about plans for European 220-240v models yet? I think they would do well over here.