why staying wet is good for hard drives

hard drives that are already wet, that is... the ontrack data recovery experts advise that for water damaged drives:

Although it sounds paradoxical, keeping a hard drive wet aids data recovery. [The contaminants contained in water are often not visible to the human eye and will damage the media irrevocably. Residues left on the hard drive platters and circuit board corrosion will need to be treated in-lab by professional engineers.] We therefore recommend putting the hard disk in a sealed container or plastic bag to prevent it drying out until professional engineers can dry the platters and other components in a sterile environment.

if you need their help, contact them or other similar professionals.