Yes there is definitely libun used for some parts of the kitchen but that does not mean that it can be done usining only libun. Also, blow torches are typically used for libun kal which is also questionable as to whether it can be done on Pesach. The Pri Megadim says not but I can see R' Belsky not following that psak when necessary due to some kashyos on it.
When I was a bochur, a friend offered me to come along (for pay) to help kasher a hotel in the Catskils for Pesach (under the OK).
At some point we took the pans that would go into the oven, and started to do libun (גמור). Needless to say, anything we tried doing this on was rendered useless! Some time into the job a upper level mashgiach came (IINM it might have been R' Dovid Steigman A"H) and said that as a matter of policy, no ליבון גמור should be done, as it is either not done properly, or it destroys equipment. ליבון קל is used in lieu of הגעלה, where that is appropriate.