David,
save cash to buy a new one
The cure woun't last for a long time cause the water will have done some major damages to the bearing already.
I've tried the same a few years ago (12 to be precise)
It's cause they poor design a drain hole above the axle, instead of below the axle.
More pics on http://www.mgfcar.de/wiper/ scroll down
Finally the bearing went bust and I had to change it.
And if you like a new one, then use the much cheaper Land Rover p/n DLB10153. Will fit with connector swap.