Removing accumulated lead, copper, and carbon helps to prevent the can from locking onto the mount, and prevents misalignment. If you have a bunch of fouling on the teeth of the mount then the teeth of the latch don’t have as much to grab onto. It doesn’t directly help extend the life of the can, per se. If you can afford the ammo to wear out a good can, esp one with stellite or inconel baffles, then you’re a lucky person, and you would just need to sent it back to the manufacturer to get recored/serviced. Regarding legacy AAC cans, you can have them rebuilt by the new AAC. It’s not cheap but it makes them almost entirely new and perform better. They are also doing latch repairs. Since the new company is not the old company there will be a fee, about $100.00, and they make it easier for the user to DIY down the road because the modify the blind pin setup so you can drive the pin out the other side. The resto mod program also make the back end hub compatible, and they also offer their STAMP mount so you can use hub cans with 51T muzzle devices. Good stuff from the new AAC.