Consolidate cells with multiple names into a single column with one name per cell

I receive an excel spreadsheet with single column of names: Up to 5000 rows with 1 - 30 names per cell (names are delineated by commas):

Example
----------
NAME
betty johnson,bart wong,alissa villa,marlee rodriguez,amy luce,isaac pierce,janet gales,david green,pete davidson
david green,demetrius washington,alissa villa,mike harris,tom serret
amy luce,angel cosh,david green,alissa villa
amy luce,
...

Would like to consolidate into one column, multiple rows, one name per cell, with duplicates deleted:

Example
----------
alissa villa
amy luce
annette sanborn
barthomele kramer
betty johnson
...