Many builders are hesitant to clean an intake manifold in their glass bead machine for fear of trapping contaminants.
I bake the manifold in an oven, which turns any grease or other deposits to ash.
After that, I wash the manifold in a hot tank, which removes any loose residue.
Then I glass bead the surfaces, knowing that there’s nothing sticky for the bead to lodge into.
I then rinse the manifold again in the hot tank, followed by a hose rinse through the runners.
I’ve never had a problem with trapped contaminants.