(1) Make your conservatory weatherproof again.
(2) You can get waterproof sockets for use outdoors - you could fit one of those!
(3) You could probably dry the socket out with hot air from a hair drier say, but depending on how long the water has been in contact with the inside of the socket, it could well have cuased a lot of internal corrosion which will remain even when all of moisture has been removed - which could cause high resistance and overheating.
Given that a new socket patress is fairly inexpensive, the best thing to do is replace it!
J, March 2008