I usually just order maps alphabetically. the achievement_ servers show up then, use ctrl+select to select multiple then blacklist.
Then order by maps again. This will order them alphabetically from z to a so then you'll find vsh_, trade_, tfdb, slender, etc. Blacklist those.
Then either scroll down until you find more groups of those types of maps or use the maps keyword search thing in the browser (dr_, cp_orange, mario, etc)
note: if you wait for too many servers to load the game can't handle ordening them alphabetically anymore. CLick Refresh then immediately orden alphabetically by clicking Maps or it might not always work
Then you can search for the server tags. 10x usually works, but crits also shows servers with the tag nocrits. Not sure if adding quotes helps, haven't tested that yet.
then you can search for Saigns, Nightteam, Skial, etc depending on which terrible server provider you want to blacklist. Saigns is European but Nightteam and Skial are global? Not sure about Nightteam.
It takes a bit of work. When I do a regular search these days I have about 600 non-blacklisted servers show up and 800 blacklisted ones. And I haven't updated my blacklist in a while so there's probably about 50-100 servers I need to blacklist still. The amount of shit servers in TF2 is inexplicably high
Also what spartan and gatsan said helps a lot and is probably a lot better. i just prefer doing it the hard way