Ditto on the messy part. I picked up some of the CVA foaming stuff on clearence from Walmart some time ago. I put the nozzle into the muzzle and pushed the cap for maybe 3 or 4 seconds and foam was coming out of the nipple and all over the place. Some also came out of the muzzle due to the nozzle plug thingbeing vented. If memory serves it suggests you leave it in there for an hour and let it do it's thing, then wipe the bore with patches to remove whats left. I could be wrong about the time but it seems it was more than 10 or 15 minutes. It seems to clean pretty good but not any better than my regular cleaning methods that only take maybe 10 to 15 minutes total. If the gun is real dirty or you need to do some other things while the gun soaks it could work for you while your away. Or if you have several guns to clean, you could squirt foam into each and let it work, then go back to the first one and finish them in the order you did them in.

If you can get it on sale like I did for around $3, it would be worth trying without much investment.