I heard the other day that you can now buy headsets with a cartridge bearing that solves all of these problems.
In my experience they don't solve the problem. The grease used in them is a very low amount, not brilliant for waterproofing and the seals are not watertight. I routinely re-grease brand new headset cartridges with marine grease and have the whole cartridge caked on the outside with marine grease too.
Favorite quote on Retrobike:
Not worth the petrol to take it to the tip so it's down to the angle grinder to make it small enough to put in the wheely bin.