Reset date/any format field to empty?

I have a set of fields values that need to be made empty again.

I used "Change Data Value" in the flow step and applied the rule - If "attribute1" IS NOT EMPTY, "attribute1" New value _________ .
I did not find "Is empty" for the new value. The attribute1 takes formats like date and string types.

I run the campaign w/o any value (like in the screenshot) but the value did not erase.

Is there a better way to reset to "blank/empty" values for these attributes? Thanks in advance.