K'Balo Kach Palto

We have a klal in kashrus called "k'balo kach palto". This means that the same way a utensil absorbs tarfus, that is the same way you need to take it out. L'mashel, if a pot became traif by cooking something over fire, then you need to kasher it with fire, a process called libun. If it only became traif because you boiled tarfus in it, then using boiled water, a process called ha'galah would suffice.
The Rema in Orach Chaim 552:1 says that ha'galah has to be done with water that is boiled (roschin)(which is 212 F/100 C). The question is what happens if something became traif by boiling tarfus at a temperature less than the boiling point. Do we say k'balo kach palto and you only need to do ha'galah at the lower temperature or do we say all ha'galah must be done at the boiling point. To put it in terms of lomdus, yesh lachkor, is the din ha'galah a din of k'balo kach palto and therefore a lower temperature suffices or is it a din in roschin, boiling water and kol z'man the water is not boiled ha'gala doesn't work?
This chakirah is brought down from Rav Soloveitchik zt"l in in Shiurei HaRav on Basar B'Chalav/Ta'aroves. The Rav says a nafka mina would be a pressure cooker which gets to a higher degree than boiling point. If you say ha'gala is a din in k'balo kach palto, then you would need to kasher the pressure cooker at a temperature higher than boiling point. However, if it is a din in roschin, that the water just has to be boiled, you only need to kasher the pressure cooker at 212 F/100 C.
Bli neder, next week I will mention what the contemporary halacha seforim bring down from today's poskim. Stay tuned...