“Gun cotton was an old form of explosive. But it can be very dangerous.”
You are far more knowledgeable than I.
I have noticed many Ukrainian photographs and reports do appear to reference the huge “cotton” clouds that form following the bombing. But, maybe I just view the images that way.
FYI
https://www.britannica.com/technology/guncotton
https://www.youtube.com/watch?v=KBVBELMq20U
https://www.chemistryworld.com/podcasts/guncotton-or-nitrocellulose/9107.article
There are experiments on youtube that illustrate making of gun cotton, largely for magic stunts. I do not recommend playing with it. As a propellant, it is not usable as a smokeless powder substitute. The flash is too violent and purity of ingredients is very critical.