Need some advice

I was trying to clean my .22 rifle today (S&W MP 15-22). The barrel was quite fouled to the point that the fittings on the flexible cable I have in my cleaning kit wouldn’t fit thru, so i picked up a threaded rod with a T handle. I put the rod thru from the business end, dipped a brass bore brush in solvent and threaded it on to the end of the rod. I then proceeded to get the bore bush completely stuck about 4” down the barrel from the breach end…

Any advice on how best to get this out? I’ve been using a dropper to try and get a combination of solvent and gun oil down the barrel while the barrel while it is vertical , and I let that sit for about 8 hours so far and it still won’t budge.