Military surplus 5.45x39 ammo is still corrosive.
The Russians decided it lasted longer in storage and works more reliably in extremely cold conditions.
The commercial ammo is non corrosive.
As for as flushing out an AR gas tube shot with corrosive ammo, carb cleaner has no effect on the corrosive salts. If you want to flush the tube, use water.
As far as cleaning a standard AR gas tube, you have super heated incandescent gas at 2000 degrees and 20,000 PSI coming down the tube. What's going to resist that that could be cleaned out with anything?
If you have a gas tube problem, you replace it.
I talked to my buddy today, who's a Match shooter. He says one of the men in his club has an AR with over 8,000 rounds through the same barrel and gas tube, with no problems and it's still accurate.
In the military, get caught sticking or spraying anything in a gas tube and your Sergeant will stick something up your gas tube.