Remove duplicate value from dictionary without removing key

Remove duplicate value from dictionary without removing key

I'm new to Python and am having to learn by trial and error, but I haven't
been able to find a solution to the problem I'm having.
I have a dictionary that looks something like this:
myDict = {'key1': ['item1', 'item2', 'item3'], 'key2': ['item4', 'item5',
'item6'],
'key3': 'item7', 'key4': 'item8', 'key5': ['item1', 'item2', 'item3'],
'key6': 'item7'}
I need to remove duplicate values from the dictionary and replace them
with an empty value (""). Found a couple solution on here but they are
working as intended
for key, value in myDict.items():
if values not in key newDict.values():
myDict[key] = value
else:
myDict[key] = ""
print newDict
This is removing all the values and is outputting
# newDict:{key1: '', key2: '', key3: '', key4: '', key5: '', key6: '')