Might get round to trying this at some point, although I’d have to cut up one on my original exhaust pipes, so maybe not.
youtube.com/shorts/lW5MTH97tPQ?feature=share

I stopped your video at maximum close up [& a very good job of the video you did too] then took a screen shot & expanded it right up big. In my humble opinion it needs a burn out. Is the only way to be sure but there's burning out & Burning Out so has to be flaming hot not just smoking hot. I used to blow compressed air through one totally on fire but nowdays i'd try my leaf blower which i recon would work good.
Here's a video that looks pretty good for what you need to achieve. Anything less isn't good enough. I used to get it going mad with the oxy-accetylene plant at work then the compressed air in & let her go. Probably a bit brutal but nowdays i'm too tight to buy gas for my welding plant at home so i put anything of mine in the rubbish fire when need be. Think i've shown a pic of my 100 twin header pipe just show the extreme of what can happen over 50 years. I'll see if i can find it again. That angled spark arrestor in yours is a favorite trap for stray carbon lumps getting caught or just generally growing in there. If you use the paint stripping heat gun like in the video i'd try burning it from both ends separately just to be sure.
Just realized this post is 6 pages long so i've likely bored you with all this before.

photos.google.com/photo/AF1QipMpZzq-W8Em...UIo7outWmTThsZos_Ve2
 

Wow, serious backfire

Pipes very rarely get clogged so badly they are completely blocked. An easy way to clean a pipe out, is to put it on a bonfire, which should burn out the unburnt oil and other gunk, that usually clogs them up. Just need to be careful it doesnt get so hot it melts.

Yep the spiral looking arrestor which you can't see through gets stuff caught in it if loose carbon bits rattling around.
My AG100G farm bike they have a straight through wrapped baffle & off down the farm then would go strangled & slow. Out with the baffle & a round ball of carbon in the end. Became too regular so shook the pipe out & ran minus the baffle for a while & was good when refitted. Should've burnt it out but--next time. Looking down in yours we used to knock the arrestor in off the spot welds then shake it back out. [not necessarily on a 360 but that type of arrestor when blocked]. Of course i probably wouldn't do that nowdays & especially in the US, just burn it out. In the old days more noise meant faster!!--well sounded fast!!.

Yes we would also knock ours out too