"Spring to Life", which releases tomorrow ... giving us a real-world parallel) than it is to say the ancient builders moved every Ghast into the Nether, leaving no traces of their species behind ...

called a Dried Ghast, lying on the ground, take out your pickaxe, scoop it up, and bring it to the Overworld, where you can dump a bucket of water on it and wait approximately 20 real-life minutes.