IFDB: Blocking certain users

If I wanted to block a certain user on IFBD, is there a way of doing this? I’ve found the filters page which has an option to “Plonk” users and hide their reviews from me, but I can’t find a way to enable this.

I’m asking because of the wonderful IFforClassroom user who’s posted a dozen ‘reviews’ recently consisting of “This IF work has an average grade level of about 5. It should be easily understood by 10 to 11 year olds.” Blocking him/her so I can see actual reviews would be nice.

After much head scratching, I finally found the option. Pity it’s not a little more obvious though.

Incidently, how accurate can that thing be? I wonder how it’d rate “For a Change”.