Effect of submerging a laptop in isopropyl alcohol without removing batteries
Pure isopropyl alcohol is not conductive...but minor contaminants (such as those that may be found on a PCB board after manufacturing) will cause it to become conductive. I would not do it ever.

As for consequences...explosive lithium fires.

If I really did not want to remove the battery, I would make a makeshift vacuum chamber to try and dry it out.