Spent some time with some chemists talking about how to dispose of the dip. They recommend using a pot or pan that you intend to discard, pour the mixture into the pan, heat the contents slowly, do not boil, allow it to evaporate. All of the lead oxides, antimoney, and other stuff will precipitate, but don‘t go sucking up the fumes for fun. Eventually the dry pan can go to recycling or trash.
In solution the lead oxides are quite dangerous because they pass through skin pretty easily. Similarly, if you get a good boil going the vapor will include particles that can be absorbed through your lungs or eyes.
So, outside, disposable pan, low heat, and patience.
There are folks on the internet that suggest adding table salt to the solution to precipitate the metals. This apparently can work some with some heavy metals, but you'll never really know so the solution doesn’t become less dangerous.
BTW, dip will eat steel, either carbon or stainless, given time.
Last thing, when you take things out of dip don’t brush them since that puts everything in the air. Have a second container of water that you use to rinse and brush. That water also goes in the pan.
