COMMENTS batch formatting

Hi to all

I have a huge library and I added books descriptions inside "comments" by copying and pasting description (synopsis) from web pages.
So the result is an incredible variety of different styles and fonts (formatting).

Is there a way to batch change the comments formatting in order to make them uniform ?

ThX by Ippopom

PS
the "erase formatting" button remove only the fonts attribute... but bakground colors and alignment remain untouched......