Carb cleaner is about all you can do, It will all run down, which ever intake valve is open at the time it will go in that cylinder. The rest will just pool at the bottom,Most will burn off at start up. you can spray to soften and wipe out as much as you can with a rag.
I personally would spray with carb cleaner, wipe it out, spray it again and put back together. Start up and then run a can of seafoam just to make sure.
when I did mine I made sure the secondarys were closed that I was cleaning sprayed carb cleaner down in there then scrub it with a small brush then suck it out with a shop vac, turn the crank to close an open the valves.