Years ago, I went through all the typical leading removal techniques up to and including steel wool and liquid mercury. The simple, easy and safest method I ever came up with was to load a few cc's of Cream of Wheat breakfast cereal (UNCOOKED!) below a cast bullet. I won't bore you with the details of how it came about (you can look it up in back issues of The Fouling Shot), but you can even shoot bullets just as they drop from the mold, without sizing, lubrication or gas checks. And you will not only not get a trace of leading, but a shot or two will remove any leading already there.
Works with almost any load too, so you don't need to use it with gut busting max loads: It WILL raise pressures a bit. But I've used it with loads so light that once the only sound was click and the sound of a .30 bullet hitting the backstop. Investigation showed that there wasn't enough pressure to push the wad of Cream of Wheat out of the bore. It had compacted into a solid mass that REALLY scrubs the bore as it passes. I guess that's how it works. The wad was so hard that a cleaning rod bounced off of it rang like I'd bounced it on an anvil, and I had a time getting the cereal out of the bore. But the bore is bright, clean and dry after each shot. In fact, you'll probably need to oil it to prevent rusting after you shoot these loads.
HTH
kbmoly