CHAIRPERSON
Apparently it's a method that's used for laboratory testing to test for traces of whatever there might be on a person's hand.  They get a bandage and you are meant to hold the bandage, which is soaked with this liquid.  Or your hands get coated with the liquid and you hold the bandage and the bandage is then sent away to the labs for testing to see what may be on the hand.  But that we can't accept as evidence, but it might be something of that nature, that testing that was taking place.