Wallhacks never work

I go on a server that has sv_pure 0

The player models are blue and red, like they're supposed to be.
But I can't see through walls, it's just highlighting players, what should I do?

all you need to do is enable the console, then open the game, join a server, Exit the server, type sv_cheats 1 in console then mat_reloadallmaterials then re-join the same server.

yeah, some servers have it so you cannot have custom textures on the walls and such