I have been working on getting my main Terraria world to 100% pure(No Hallow Crimson Or Corruption) and I managed to get the world to 1% Hallow and 1% Crimson but can not find those last 1%s. I have tried using Tedit to find the coordinates of the last blocks but that did not work and I have also tried the MoreTerraria world viewer to find those last blocks but it keeps giving me an error when I try to draw a world. If anyone has any tips or tricks for finding this last bit I would gladly try them because every solution I have found online does not help me in the slightest. I am also trying to stay away from destroying the world since it is my main world and would prefer not to look over the entire world as it is a large world which means that by the time I found it, it probably would have spread more already.
If needed here is the world download if there are no efficient tips and tricks that can work so that I may at least get some help finding the round about area the crimson and hallow is.
Best Answer
Since you have mentioned TEdit, I am assuming you are fine with using the tool.
The last tool on the toolbar, called the "Morph Tool" will allow you to change the biome of any region in its brush. Under the "Morph to Biome" option, select "Purify." You can now use the morph tool to remove corruption/crimson/hallow in the brush area.
Turn the brush size up to max and move it across your world to purify it.
An alternative is to create hellavator shafts across the map spread apart at approximate 25 tiles and spray the Clentaminator across both sides.
Note: I will add images later today.