You can use uBlock Origin extension and add them into a filter so you won't see them or any specific words in feeds.
Then you can go into the Dashboard of the extension > My Filters and add in lines like this to filter out anything you want.
lemmy.fmhy.ml##.post-listing:has-text(TEXT_FILTER)
The TEXT_FILTER
is case sensitive. So, you can make multiple lines with the same word if needed. If you want to filter an entire instance from showing up then you would put in @INSTANCE_NAME