I was swapping out glow plugs on an older Duramax. One of them would not budge no matter what. I applied heat and used a breaker bar, but it snapped off flush with the head. Had to carefully drill it out, which took forever. Now I have to clean out all the metal bits from the hole. This set me back on the whole job. Lesson learned: sometimes you just have to walk away and let the penetrant soak longer.
Remember trying to get a frozen brake line fitting loose on my truck. Spent an hour fighting it, getting mad, and almost rounded it off. Went inside for a beer and left the penetrant on. Came back an hour later and it turned like nothing. That soak time is real, it's not just sitting around.
Letting penetrant soak longer is a lesson I learned the hard way too. It can feel like wasting time, but that extra soak can mean the difference between a clean swap and a disaster. PATIENCE really is a tool in the toolbox for jobs like this.