I would NOT do anything that could be traced back to you. Open a private window if you want to do this, at the very least. Do NOT use your name or email address.
Not only because some people are very likely to take any hint of criticism as an invitation to go after you like you are a weakened gazelle and they are a lion, but also because if the school district sees a review, positive or negative, it could be brought up as a violation of a social media or privacy policy. Those policies are generally incredibly vague and broad (often unconstitutionally so, but who has the time or $$ to fight that??) so that if an employee is a problem or annoyance, it is an easy thing to write them up or fire them over. Do NOT give them any ammunition.
If you TRULY want some bad reviews? Go to a public library to post them. Many, if not most public libraries wipe their servers at night so that the government cannot come in and see what people are doing online.
