What novel and unique propaganda methods have you seen?

I have seen relatively novel and unique publicity methods, such as writing advertisements on the plane, or hanging a big banner under a hot air balloon, and writing advertisements on the banner to promote our own things. These are all relatively novel and unique publicity methods I have ever seen. Once I went to a tourist attraction with my friends and saw a hot air balloon when I was playing. There was an advertisement under the hot air balloon. I think this kind of publicity is very novel. When we went there, we found many people below. Putting advertisements on this hot air balloon is a very novel idea.