Okay, I THINK I figured out how the filter thingy here works.
1. Click the Settings icon on the top right of a column
2. Scroll down to 'Advanced'
3. Put a text like this in the 'Filter out by regular expressions' box:
@.*bot\s|@someone\s|some word|more words
^ This would mute ALL toots that CONTAIN
1. usernames that end in 'bot' (but not ones that have 'bot' in the middle)
2. user @someone
3. words 'some word'
4. words 'more words'
Sadly it can't seem to filter out emoji like
Thanks to @Baxter for pointing out that using '\b' instead of '\s' also makes it work at the end of toots!