There might need to be a talk with your son, as well, to explain that not everything on the Internet is correct, real, advisable, etc.
Sorry about your laptop, thawing out for several days and ensuring it is 100% dry may solve the issue. I would definitely remove the battery while doing this and make sure the external power supply is not attached until you are confident the system is dry.
The HDD/SSD should be fine, even if the other components were damaged (won't know until later, per above).
Good luck.