I soak my barrels in Hoppes overnight, and in some cases for a few days before hitting them with a brush. After an average of 300-500 rounds through the barrel, I can get all the carbon fouling out after ~5 patches. I use a plastic Gatorade bottle for soaking, and replace all of the solvent when it's no longer transparent.
I also have an ultrasonic cleaner:
http://www.sonicsystemsales.com/home.htmlI use it twice a year or so on my pistols, but it's not the time or effort saver people are lead to believe. If you have to scrub a barrel with a bronze brush to get it clean, vibrating liquid isn't going to do as well a job, and it does nothing for copper fouling. Where I've noticed the ultrasonic shines in in cleaning the frame, and all of the little nooks and crannies that never get cleaned properly, even if the pistol is completely disassembled.
What I do when I use the ultrasonic is to completely disassemble the pistol, and clean each part individually (including the barrel) before running it the the cleaning solution in the tank. I do this to both keep the tank solution as clean as possible, and to inspect every piece for unusual wear or fatigue. You could also do a simple field strip and cleaning, but you will be changing the ultrasonic solution more frequently.I run all the parts through the cleaner for 4 minutes, and then the barrel itself for another 5. Be careful - the ultrasonic can remove paint and some finishes, or discolor some finishes if run for too long a time.
Immediately after being run though the cleaner, I dunk everything in distilled water and gently agitate to get all of the cleaning solution off. I then towel dry and then hit everything with compressed air to remove all of the water from the parts, and run all metal parts through the lubrication solution for 4 minutes. This adds a corrosion protection layer to the bare metal to prevent it from rusting or tarnishing. You want to make sure that everything is as dry as possible when running through the lube, as any water will dilute the solution over time.
I then place everything in a cardboard box, with a 100 watt incandescent bulb in a shop light a few inches above the box. This causes the lube to penetrate the metal, and most of the excess to evaporate off. After 24 hours I wipe/blow dry any remaining lube, lubricate with CLP and reassemble. Note that the ultrasonic lubrication is actually more of a protectant than lubrication. You will need to use your lube of choice during reassembly. If you ran your gun with only ultrasonic lube, it would chew itself up in a very short period of time.
http://www.midwayusa.com/product/147773 ... n-1-gallonhttp://www.midwayusa.com/product/461763 ... e-1-gallonAn alternate method would be to skip the lube step in the ultrasonic, and simply soak every part in a penetrating oil like CLP overnight. This would actually be better than the ultrasonic lube in some ways, as the oil that has penetrated into the pores of the metal will act as a better residual lubrication if the pistol runs dry. It's a lot messier, as you'll have to hand dry every part dry - it won't evaporate like the L&R lube does. It's also better to fully disassemble your pistol to ensure that every part both gets a coating of oil, and is then fully wiped dry. If you miss a spot it will be subject to rust as the cleaner will have brought everything down to bare metal, and is highly susceptible to corrosion. Anything left wet that doesn't need to be is a fouling magnet, that can gum up the works over time.
So I think you get the point here, an ultrasonic isn't an alternative to routine cleaning. Its an additional method for doing a deep cleaning on pistols that see a lot of use, or that you do not want to fully disassemble for a traditional deep cleaning. While it may only take 4 minutes in the tank, the prep and post work take considerably longer, and don't really offer much of a time savings compared to conventional cleaning.
As a side I have recently been reconsidering my cleaning regimen as I've started looking into what happens in the barrel during both shooting and cleaning. Basically, the first few microns of the bore undergo chemical, structural, and metallurgical changes when fired. Carbon from the powder is forced into the pores of the barrel under extreme pressure and heat, increasing the carbon in the metal making it considerably more brittle than the original steel. Microfractures occur and other chemicals such as nitrogen also affect the surface of the bore. The effect is that any mechanical cleaning *does* remove extremely small amounts of the bore. The surface of the bore is no longer the original steel, and the whole notion that a bronze brush is softer than steel and can't hurt the bore is a fallacy.
The idea is to maintain a consistent level of fouling without ever over-cleaning the barrel back down to bare metal. An ultrasonic would likely screw up this approach to cleaning, as the ultrasonic vibrations will tend the remove fouling from the bore in tiny flakes, rather than work through the various layers that have been deposited. I'm thinking a dry boresnake through the barrel 10 times while hot after a shooting session may be all that's needed for regular barrel cleaning. I'll still clean down to metal for a deep cleaning, but I only do those twice a year or so, compared to once or twice a week for my normal routine cleanings.