How to Decap ICs with Rosin

This video shows my attempt to decap 3 ICs (2 identical Bluetooth SoC BGAs and 1 STM32F103) using boiling rosin aka colophony. There is scattered information in article form about this process, but some contradictory information about how long to boil the ICs, and how to process them afterwards. My attempt was only mostly successful on 1 of the 3 ICs I tried, but I learned a bit during the process and would likely have better luck if I tried again. It also appears that the epoxy formulations of various ICs vary quite a bit, and it will take your own experimentation to find the right heat/time combination to work.
Coming soon, I will show a video on how to decap simple (non-stacked) ICs using sandpaper, which is way faster (~10 minutes vs ~2+ hours) and safer (no rosin fumes to deal with) though has a higher chance of IC damage.

[@BakukuMods]

Is the chip still functional or is this purely for silicon inspection?

[@zakzwijn8410]

I tried doing this but without success. Had an old Asus P6T motherboard, but nothing happens to the chips, not even with the hot air gun at max temperature of 650 degrees centigrade. Only created a big mess. I had success with sulphuric acid based drain cleaner. 30 minutes of heating and only the die was left