The opposite of hate speech is praise. You can use it as much as you want, it will not cause any resentment or annoyance. Praise builds too positive online culture.
Do it first listing of tubettasfollowed by students in your class.
Select from small groups in the list one tubettan, preferably one you don't know well before. Watch one of the tubett's videos and think about what positive comments could you write about the video.
Return comments to the teacher.
You can also post them directly in the video comments if you have Youtube IDs. The tubetto will definitely feel good!