Been here for 60 years, never heard of anyone baking their spark plugs before.
Unusual (admittedly), but it worked. No one else could start their cars. After that, electrical outlets were installed where the cars parked (apartment complex in Kasson, Minnesota).
Might be something to remember if someone is having trouble.
This was on a V8 engine on an older car, and it took a few minutes to remove and re-insert.
I only did 4 of the 8 spark plugs...