I don't know Ikelite's, but if the battery compartment is sealed (that is, if this flooding didn't affect the internal components in the main body of the strobe) like in Sea & Sea strobes, I have in the past just cleaned up the inside of the strobe with rags made from old t-shirts and long, thin, sturdy pieces of wood (bamboo skewers, specifically) and a little bit of water. With some patience you can make the inside look almost as if nothing happened.
In the Sea & Sea strobes, I disassemble the strobe cap to clean it after a flood since it has an intricate design (and I clean it the same way, with a rag, a little bit of water, a bamboo skewer and some patience), but as long as it's well rinsed and dried, some may consider this not necessary.