MrDonnyAir
He's referring to Agent Orange, which was a chemical defoliant used to get rid of jungle canopy so we could see the VC and North Vietnamese better by air when we were bombing. The Soldiers and Marines on the ground ended up getting it on them while walking through the jungle, and AO was bad, nasty shit... lots of Vietnam Vets came home sick from it, and many eventually died of the cancer and other illnesses that it ended up causing.