I hate to kill a dead horse but two things make my LNC2 belly super
clean. First, turn down the exhaust pipe tip 25 degrees.   I get
absolutely no soot after doing this no matter how rich I run.  Second,
use an oil breather seperator and run the overboard (relatively clean)
hose out onto the exhaust pipe.  Before these two items I tried ever
single item mentioned.  I've had enough simple green in my eyes to blind
me.  Since then I need no belly cleaner aside from a little soapy rinse.

OTOH the very best advice I ever got for belly cleaning (back when I had
to clean mine) was a little GO JO hand cleaner(without pumice) on a rag.
How could hand lotion be bad for paint?  It's great.  Trust me on this
one I've spent as many hours cleaning my belly before the exhaust tips
as it took to build my plane:)  Wipe it on, then wipe it off with a
clean rag.  No drippy gooey mess, mimimal effort, no chemical laiden
puddle to lay in, no paint damage, very fast painless experience all the
way around.

Larry