I follow a few Twitter feeds that give me a lot of repetitive false positives. I still want to follow them, but needed to cut back the clutter.
(1) Create dummy twitter account (for example, "custom_stuff_for_me")
(2) Create a Yahoo Pipe that imports the RSS feeds of the twitter accounts you intend to follow/filter.
(3) Add a filter module to your Yahoo Pipe that blocks some of the false positives.
(4) Make your Yahoo Pipe public.
(5) Use a service like twitterfeed to suck the RSS from your Yahoo Pipe and push it into your dummy twitter account.
(6) Tweak the twitterfeed settings to push the maximum number of RSS items into your dummy twitter account.
(7) With your main twitter account, follow your dummy account (and un-follow the accounts you were trying to filter).
You're done. Adjust the filter on your Yahoo Pipe as needed.