I had some white fluffy bullets before, lol..
Fill a container with apple cider vinegar, just enough wo when the bullet put in bullet down wont cover the brass {my bras was clean just the lead was corroded}..
Then put your bullets in a circle and wrap with an elastic, put them in the vinegar, let them soak.. wipe them off in a bit and go shootem...
My wet bullets were .45acp semi wadcutters, I let them soak a day or so, I had 1200 of them to clean up ar $.30 each it was worth the effort for me... I used gloves and steel wool after they soaked, they looked brand new after that, I got the tip from my gun smith, he also said I could stick them in poatoes, I didn't get all the details, lol, the cider vinegar sounded much easier..