Here's a suggestion. Go to WallyWorld and buy a plastic dishpan. Put in a 1/4 cup of dishwash detergent and fill with hot water. Stir it up. Fill it with wheelweights and let them soak overnight.
In the morning, scoop the wheelweights out by the handful and rinse them in hot tapwater until they're all well rinsed. Spread them out on a couple of layers of paper towels and let them air dry.
When they're all nice and dry (I usually let them air dry overnight), melt them (be sure to flux & skim) and pour them into ingots.
That way, you get all of the messy stuff out of the way at once, and whenever you're ready to cast bullets, just heat up the ingots.
If you're using a furnace, when you finally get the temperature adjusted to where it casts well.....don't touch it! When you're done casting, just uplug it, and leave the temperature where it was.
I, personally, don't use 50/50 solder.....I just cast straight wheelweights.