Weighted pewter is a thin pewter shell filled with what has been not affectionately referred to as "petrified yak dung". Most often seen in candlesticks. I think this stuff is an abomination that when it melts makes a royal mess of one's pot, equipment, basically everything it touches. I think it might be a near relative of horse hoof glue.
So how do folks get the pewter and avoid the crud inside?
I have peeled the pewter off of the filler, not often easy, especially if the object has a lot of ridges and grooves. Also the "shell" is thinner than a cheap beer can so much work for little reward.
Have pried the bottom off and beaten the object against concrete to bust up the filler until it comes out in chunks, then tear it apart to dig out the chunks that don't come out with a screwdriver.
I started out just melting and trying to skim off the filler when it melted. Aside from the smell of melted glue it makes a huge mess. Fluxing with sawdust can remove a lot but slotted spoon, pot, stir stick, whatever I pitch the skimmings into all end up with the filler stuck all over everything and I'm cleaning it off for the next 3 batches.
I'm thinking maybe someone has a process that works better than what I have tried. Which is currently setting filled stuff aside to avoid melting it down unless I have a need for it. Wish wife liked these candle sticks more than she does the vases and pitchers, those have lots of easy to salvage weight. :-)