How to mass unfollow or bulk unfollow on Twitter
Our preference is using services like http://bit.ly/1hGw4t. While not free, they do allow you to unfollow in an automated fashion on a regularly scheduled basis. They don’t mass unfollow in one stroke but do so a few at a time all day long. This keeps Twitter at bay and also helps you grow your account. In addition to the bulk unfollow function, Tspin http://bit.ly/1hGw4t also provides filtered following, smart tweets, scheduled tweets, rotating profiles and automated DirectMessages. Well worth the nominal monthly fee.