It all depends on how hot your components may or may not get.
Capacitor temp ratings will sometimes give you a clue e.g. 85C or 105C.
Many power supply caps are rated at 105C because they can get quite hot, in
many cases caused by the component next to them on the PCB.
Silicone netural or acetic cure are usually rated to well over 200C Deg
temp, some over 300C. And usually stays where it is applied without moving
Rubber cement is/was another commonly used product, it can be slow drying
and usually runs downhill from where it was applied
reasonably heat reatistant
when dried.
I hate them both, makes repairs on SMPS and LCDs that much harder.