If you use the search on the Cletus page (or other search engines), you get a page cannot be found message when you click on sites that use "https" that are known to be blocked by the web filter.
See the screenshot example below and note the "https".
The web filter blocks https requests for blocked categories, but does not present a message.
Remove the https and replace with http and type in URL in address bar. You will get the Barracuda block page and you can bypass.
(A picture of the address bar is below. You would type in http://facebook.com, for example.)