I had problems with some apps building huge temp fikes like that.
I looked on Quora (before I found Android Forums) and did find an answer that seems to work well.
First, you must locate the folder in your File Manager.
Delete that folder, but remember the exact name of it.
Make a new item, but this time make it a file instead of a folder.
Give it the exact same name that the folder had.
Now when that app tries to build up a temp folder again, it will see that there is already a file by the same name there, and will not build up that info any longer.
I think that the way this works is that no two items can have the same name at the same location in your files.
When the app tries to make the folder, there is already a file by that name, so the system stops the folder from being created.
Please be sure to pay attention to the use of the words 'file' and 'folder' here. It is very important to make this work.
If you make a folder instead of a file, the app will simply overwrite your folder with its own, and it will continue to grow again.
But the app will not be able to overwrite a file, because it is trying to make a folder instead.
And if there is a file with the exact same name as the folder that the app is trying to create, then the system blocks it.