I once had the same issue and took mine to work and put it in a heat washer thing that engineers use to steam wash parts of machines and worked a treat.
this happened to me once...
i just a couple of old mouse mats for grip. The rubber size of them is really good. The dye tech mat is even better. Try putting the barrel in a gun and placing it on the edge of a table. as you loosen the reverse thread on the 2 piece it will tighten in the gun, and the gun wont spin round. But be carfull not to get the back stuck on the gun. Hope i explained all this right. It makes sence in my head.
That is the only reason I have not tried the 'Screw it into the gun' idea. Knowing me, I'll get the front out and the back will be stuck in the marker lol.
Big guy at the gym is a good one lol
This seems to be quite a common issue. More than I expected TBH.
I really dont want to use tools as I just know it will damage the back