If the babbit has transfered to the bearing surface in the head, yes, it can be cleaned off.
The coating on the cams can be taken off without any problems.
I use a fine wire wheel on a bench grinder.
It will remove the babbit, without hurting the base material.
I have never had a problem with cams that have had the babbit removed.
All reground cams such as Schnieder, and welded,
and reground cams have the babbit removed,
and I here no problems from people running them either.
Now if the damage is severe, to the point of the aluminum in the head is groved,
or the cast iron of the cam is groved a lot,
that is a whole different story........