What do you experienced shop-working old timers recommend for cleaning the intake and upper cylinder area on an LH2.4 engine?

I've read too many stories about the billows of smoke resulting from Seafoam application. So I'm not going to put that into my 270K miles engine.

I'm currently running through a tank of Gumout injector + valve cleaner which is designed to be put in the gas tank. The version for "high mileage" engines, over 75,000 miles! I've driven two miles on it so I have absolutely no results yet.

What else is good to use to clean the intake and upper cylinders? The Gumout injector cleaner makes no claims re. cylinder walls, only injectors and valves.

Maybe use Gumout carb cleaner, spraying directly into the throttle? After removing the flexible hose and disconnecting the AMM? I'd think it would idle well enough with the AMM disconnected to do that treatment.

I did remove the throttle body and cleaned it thoroughly, about a year ago. I'm sure it's not pristine but I imagine it's pretty clean.
--
DAMHIK: Don't Ask Me How I Know - - - Sven: '89 245. 951 ECU, open-front airbox, E-fan, 205/65-15's, IPD sways, E-Codes, amber front corner reflectors. 500 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).