I don't know what happened to them, but it does appear they spent time under water. I am in agreement with everyone on that front.
That said... I doubt I would ever attempt to use them on a gun, or at least a blued gun. If they were soaked in water, I would wonder what type of water. I would also be fearful of them being submerged in salt water. Like if they were salvaged from a Katrina gun, I would fear them rusting my gun.
If I were absolutely sure I was going to use them on a gun. I would strip them down to bare wood, wash them several times with soapy water, and refinish them with something that would completely seal the grips. I would seal both sides...
I know factory grips can be worth a mint, but they are not worth potential gun damage without taking steps to mitigate it.