TextFormatRemove ( self ) is a function that can be set up as an auto-enter calculation (clear the do not replace existing value option). It is not a script and can be copy/pasted from one field's set of options to another.
I don't know off hand what that "synchronize" option is intended to do, but suspect that removing the formatting from text as it is being pasted is not the purpose. (a quick check in FileMaker Help isn't perfectly clear, but I think this has to do with setting up fields to work better when inputting less typical languages than English or most European types.)
Two other options:
I don't recall them off hand, but there are keyboard shortcuts for pasting unformatted text.
You can keep your text field unmodified--which allows for formatting text within the field when needed, and use a calculation field defined with TextFormatRemove for use on layouts where the formatting must be removed to get consistent appearances between multiple records in the report.
Thanks for the quick response!