Well, I’ve tried to watch a few You Tube videos where they had before and after borescope videos using various intake valve cleaners and the ones I’ve seen so far have not impressed me. However, they are very good at cleaning your wallet. If someone has a good video showing what they think is a worthwhile improvement, I’d be interest in seeing it. Please post the link so we can all share the info.
I'd also be concerned about doing it after 150K miles. Are the "chunks" that might come off large enough to hurt anything inside the cyl (or edges of valves) at that point (and for that matter, will sprays even remove that much gunk). Almost think it is something you should either do quite often in that 150K, or just pay someone to clean it mech when you start to egt degraded perf )if/when).
I'm adding meth on my 2.7 fusion, which gets top grade gas, dual connection oil separator (since new) and
has only 59K. Hoping that keeps it at bay. Now the Women's 2.0 escape though, uses cheapest gas, no oil sep, and already
has over 80K. Just going to wait and see on that one.