This is helpful in the beginning to affirm ones suspicions. It does nothing to move the gaslighter.
Once you are confident in your assessment, drop this one! Otherwise, you begin living into the scenario the gaslighter is creating more deeply.
Instead, use your new found confidence to create a reflection mirror. Be honest but emotionally immune. "Hmm, I wonder what's behind your statement?"

I am not claiming this makes for a good relationship, but one's own emotional health is one's responsibility.