Hard carbon removing, help!

[Murray Brook]

I've used Fritz and find it work real good. The Green stuff.

 

[HTSmith]

put the guide on the rod before you put the brush and JB'd patch on the rod

Another gem. Why can't I think of stuff like that

 

[Martin52]

Does the EGR valve cleaner spray remove carbon deposits?


A Winning in the Wind video recommends using methyl isobutyl ketone, which is a solvent for nitrocellulose, which is the base for gunpowder.
Do you have any feedback on this?

I have not used EGR valve cleaner but I have used this:

Nulon - Pro Strength Throttle Body and Carby Cleaner 400gram

Nulon Pro-Strength Throttle Body & Carby Cleaner is specifically formulated to quickly and easily remove gum, sludge, varnish, grease and dirt build-up from carburettors, throttle bodies, automatic chokes, PCV and EGR valves.Benefits: 400Gram Aerosol Can Dissolves carburettor deposits inside and...

theskylineshed.com

Regarding methyl isobutyl ketone, yes, Winning in the Wind (@Keith Glasscock) has reported on this being an ingredient in Free All.

Free-All Penetrating Oil

Free-All Penetrating Oil, RE06 The original rust eater, Free-All Oil penetrates rust, scale, and corrosion to free rusted or frozen parts and assemblies quickly and easily. This deep penetrating oil loosens tar, lead, grease, and carbon and graphite deposits. A rust-eating formula makes this...

www.dultmeier.com