The search filters of FreshRSS look thru HTML source and not the rendered text. Search is useful for searching by public readers, filters help is marking posts as read. 

This way you can show the public curated posts only and remove spam. Not case sensitive, space is AND and OR needs to be put. Filtering articles

" toby " and "toby" and " toby" are not the same. Observe whitespace.

"spooky casper" is not the same as  spooky casper 

The first one is a string search and the second AND search

It would be good feature to add delete button in each post, and also purge read articles.