import re


def clean(l):
    """
    Removes nan and personal pronouns from l
    and returns a list of NER uniques.
    """
    non_nan = [re.sub(r'(?:^|, |s|S|)(?:h|H)(?:e|i).?(?:, |$)', '', str(item)) for item in l]
    non_nan = [item for item in non_nan
               if item != 'nan' and item != '']
    return list(set(non_nan))