tiktok's search sucks and doesn't seem to interact with their algorithm much. it's kind of silly but to bootstrap it you need to flip through the feed until you happen upon something you like, then like that video. you can also follow the person and scroll through their profile to like other of their videos. it takes a little while (couple days) but once it starts spinning up it gets really good at showing you what you want. i ended up uninstalling it since it was too tempting to waste time on (now i waste time on twitter, eh)