This is not true, electronic circuits can work fine after being dried for a few days on a radiator or in the airing cupboard (I have fixed dozens of laptops this way after water damage) they often need stripping and cleaning afterwards though, you will also need a new battery!
For complete drying / cleaning you can send your phone to my shop, details can be found at www.preselicomputing.co.uk
Preseli Computing, March 2006