If its not sealed the best thing I found was a tip from one of my friends in the US, a bucket of water (about 5 litres min) but with a generous squirt of fairy liquid (or indeed any washing up liquid), froth it up with the mop so its a lot of froth to water; then get some of the froth on the mop and squeeze out as much of it as possible, then use this to mop-it really makes the laminate clean but not sticky or greasy and also has an anti-static quality that stops it getting quite as dusty in the future. Still prefer carpets though; they don't look as cool but with laminate as my sister says 'if you don't hoover and mop it for one day it looks like you haven't done it for 10 days' xx