Saltwater exposure is extremely damaging. The camera body is very likely beyond economical repair because salt residue causes corrosion and can leave conductive deposits that keep damaging electronics even after drying.

Be cautious with anything that was attached to the soaked body. Community experience suggests a shorted or contaminated accessory can potentially damage another device, so don’t mount the lens on your new camera until it has been professionally inspected and cleaned. If the lens was also soaked, salt can affect both electronics and optics.

For the old camera, the best chance would have been immediate action: remove all power sources at once, thoroughly flush with fresh/distilled water to remove salt, then dry completely with desiccant/silica gel. Once time has passed, corrosion may already have done permanent damage.

So the practical answer is: assume the XTi is a write-off, and avoid connecting the soaked lens or accessories to your new camera until a repair technician checks them.