I suspect the fire cleansing other than in large bits and pieces here and there will be more likely in the latter parts of the 7 years of the Great Tribulation--at least the 3.5 years of God's Wrath. But we've already had a lot of forest fires in the rain forest and other places which some prophet types predicted as much as a decade before.
.
I've always had the impression the fire will be something on a large scale like a meteor or nuclear bombs.
I have not studied end times theology in any great detail so I can't say for certain.