White substance on flash shoe

[carmot]

Hi out with z7 11 on the beach were a wave caught me out and hit the camera pulled it out the way pretty quick dry it off straight away wiped it off with a damp fresh water cloth placed in a zip lock polly bag with silica gel in but after about 30mins around the flash shoe was a white substance wasn't salt more like a grease away cleaned it off it came back a couple of times but gone now camera works great but still wondering what it was and should I send away to be checked

 

[TCR4x4]

If it works, leave it alone.