the best way to clean intake manifold?

Before I put the intake on my new engine I'm about to install,I need to clean out the intake manifold because it's really caked with carbon.What kind of cleaner works best?

Should I soak it in cleaner in a big bucket?

t.i.a

I did mine in stages took it down to the local quarter wash and blew everything out of there that would move. Then sprayed it down with Liquid Wrench and scrubbed. A spray can of Liquid wrench is fairly cheap and works well on carbon and baked on junk. Next step would probably be a coat of oven cleaner and another trip to the quarter wash, but I never needed it. Final cleaning with a spray can of brake cleaner.
I do have a rather large bottle brush, I picked up at a restaurant supply place. It's designed to scrub out the big fat fryers at chicken places. 15 years old and it's still going strong, a for real quality scrub brush.
If there was someplace close with a hot tank, I'd probably take it there. I did try a salt water ultra sonic tank once, with iffy results.

brake clean.

Spray it on and let it sit for an hour or so.

deep creep... the stuff is amazing