What happens if you use high temperature PTFE tape with the heater block? High temperature PTFE tape is rated up to 550°F, which is 288°C.  I'm wondering if it would be useful for components on the hot end to prevent oozing.  Has anyone tried it?
As Andrew stated: PTFE tape should not be needed.
Tighten the nozzle with the hotend hotter than you print at and also clean the threads with a tap if you need to.
To answer your question: it would stop leakage from the threads.