I heard that panel wipe works well but I haven't had a chance to test it out. They use it to clean the panels of cars etc before they are sprayed. You should be able to get it most places they sell car parts at around £15 for 5 litres. I should be trying it out in the next week or two. I'll post my results.
I've also had purer results using freeze precip. Use less lighter fluid per pull than you may otherwise do. Allow the lighter fluid evaporate by around 50% before you put it the freezer. The solution needs to be concentrated before it will precipitate.
When you filter out the crystals most of the impurities will stay with the fluid. Allow the rest of the fluid to evaporate as there will still be some spice that didn't precipitate.
I'm pretty new to this game and am still learning myself. Keep me informed if you find anything better.
Changes come.
Keep your dignity.
Take the high road.
Take it like a man.