Tweetbot can use regular expressions to mute tweets in your timeline and mentions.

tweetbot-mute-regex.md

Hashtag abuse

Three or more hashtags.

#[^#]+#[^#]+#

Long hashtags (15+ characters): #hashtagpunchline

#[^ ]{15}

CamelCase hashtags (3+ Words): #NotSelfAware

#[^a-z ]+[^A-Z ]+[^a-z ]+[^A-Z ]+[^a-z ]+[^ ]*

Painful to read

Unforgivable word shortening: I'm near ur place r u busy?

\sur\s
\sr\s
\su\s

Mass conversations (4+ Mentions): @guy @dude @otherguy @man totally.

@[^@]+@[^@]+@[^@]+@

Retweet chains (2+ RTs): OMG RT @teengirlsquad RT @beebz I'm thinking of you.

RT[^RT]+RT

Mentions with only a URL (spam): @imathis tinyurl.com/spam

^@imathis *https?://[^ ]+$

Hello, I forked this gist and made the regexps easier to read. Some of my changes cause slightly different behavior, though, although some still match the exact same set of tweets.

Thanks for these. However, there's still a format I can't find anywhere:

Say I follow @Superman, and he constantly talks about kryptonite. I don't want to mute all mentions of the word "kryptonite," just his mentions of it.

Would I simply mute:

@Superman+kryptonite

(?) Or is the syntax different? Thanks in advance.

For the 3 hashtags one, I would have said (#[^# ]+[ ]*.*){3} 😄
Yours will not catch the 3rd hashtag completely, in a tweet such as "#magic is #cool and I also like the # sign." The third # is not a hashtag, but it still is counted as one.

In recent developments, I would add:

Mute tweets longer than 140 characters: [^]{140}

See https://twitter.com/rolfje/status/929643146002255872

Apparently that does not work correctly, and .{140} means I loose all 140 char tweets with expanded links in them. I think this requires more work.