Alcotec 24 TurboKlar
The Alcotec Turbo Klar finings does the trick in 24 hours normally and in 48 hours in the impossible cases. For finings to work best, it is important that you have degassed the brew and ideally added a stabiliser, or at least made sure that it is not fermenting any more.
It comes in a practical duo-pack, containing all you need to clear 25 litres of wine or wash. Note that it does NOT work on beer (it’s too good, you would take out the yeast you need for the secondary fermentation later).