An alternative method, run a VNC server on your home machine and then connect to it from school.
This way you can control your home pc via a webbrowser, completely unhindered.
Its pretty neat, i wish i had know of it years ago during those dull IT lessons...
http://www.vnc.com/
(You will need to forward ports if you use a firewall)
That way all you do is type your home's external ip and then the port number. Enter your password and you're all set.
If you are tired of having to remember your IP (a vague bunch of numbers) you can get it routed with no -ip.com (why the hell is that keyword filtered?)
Good luck.