Tool Recommendation for Cross Threaded Spark Plugs

So somehow I managed to cross thread a spark plug on my #7 cylinder (I'm blaming the header clearance and not the user :p) and because it was one of the first threads that was damaged, I was unable to get a normal spark plug thread chaser to even bite.

I came across this tool: Powerbuilt 14mm Back Tap Thread Repair Tool - 640811 which I had no idea existed but boy did it save me a ton of work in trying to install a helicoil or timesert. It has an expansion tap that allows you to slide it through the spark plug hole and once you expand it, you simply chase the threads in reverse. It also helps prevent metal shavings from falling into the combustion chamber this way. For $25 it was definitely worth a try.

Anyways I just wanted to recommend this tool in case anyone else runs into a similar problem. It may not work in every situation but in mine it did. The amazon reviews are mostly good, I think the bad ones are probably due to user error more than anything.
Yes thread formers rock, they are actually used in high production machining as they have 10 times the life of a cutting tap. I’m not sure they would work in cast iron though, steel and aluminum they are great. Works best with thread forming lube oil formulated for thread forming specifically.