Depends on where you wish to block/filter content from!!
Alternative one.......get a good content filter on your desktop/laptop. make sure you are the only one who has the admin password so that your guys cant alter filtering rules to allow in bad stuff as and when they want. Most content filtering software downloads white/black/Grey lists from the internet automatically and updates your local database. You can always block any kind of stuff from being accessed from your desktop/laptop.
Problem is, your guys can become a little smart and borrow your neighbor's laptop which has got no filtering capabilities, hence circumventing your security measures!!
Alternative two (recommended).....Have your ISP filter content that is being passing to your link to your agreed standards....they will do so at a small cost..... I wouldn't expect your guys to call the ISP and complain that they cant get to
www.hardcore.com, they are simply connered....you may couple this with option one above as well!!
Have a non-porn day, won't you??
When I have money, I get rid of it quickly, lest it find a way into my heart.