Removing some not so nice textures...

So I've been planning to stream myself while map making, but it seems I have a little problem... I'm not sure where they came from, possibly a trade map or something, but whenever I go to browse through my textures in hammer, some pretty horrendous textures pop up that I feel would not be appropriate for the streaming platform I'd want to stream on. I don't even want to describe how these look, but I want them gone. So, what I want to know is where hammer gets the textures from so I can find them and remove them as soon as possible. Anyone have any quick answers? Thanks in advance! (Also, sorry if anyone feels this is a dumb question, or that I've been making too many threads lately!)

Berry said:

Materials for hammer can be stored in these 3 places as far as I'm aware:
- team fortress 2/tf/materials/
- team fortress 2/tf/download/materials/
- team fortress 2/tf/custom/X/materials/

If you've downloaded them from a server, chances are they'll be in the second one

Click to expand...

I'm not seeing those exact textures... Do you think that it would be safe for me to delete everything in tf/download/materials just to be safe, and see if that works?

EDIT: Never mind! I did some further investigating, and found the textures, successfully removing them. Thank you for your help!