extreme carbon and smoke buildup

I have a project that is 50,000 sq ft of interior pressure washing with carbon buildup on the metal walls.Anybody have any recipes for this kind of cleaning? I have tried both ends of the spectrum acid-base. Southsides equipment BD200 with butyl with heat worked out the best but not excellent.Would adding TSP boost the cleaning power?

Shane, Panel Bright might be a better choice for carbon. it'll take diesel stack stains off trailers.

Russ, I tried both samples from you the BD 200 and the panel bright. The orange colored bd200 worked the best when it was applied with heat.It cleans pretty good because we can only hit the surface with a 0050 ds and rinsed same way. 3500psi is not an option since there is no room for any lifts.Just trying to find a way to spike the potency.Its an awesome product but the walls we are trying to clean have not been cleaned in 20 years.

Ah yes, I recall the scenario now. Sorry.

Find a way to get a stronger mix on the wall if its got enough gylcol ether in it the carbon should roll off.