I'm pretty sure it still works from what others have noted in different threads.
Are you extracting the zipped .rar file?
Once extracted, using the correct file with the leading "."? [ .DJI.configs] You may need to show hidden files to see the file with the leading "."
Are you being very careful which folder you are placing the file? [\Android\data\dji.pilot\files] It seemed that many were not seeing the "files" at the end of the path. They have also commonly tried putting it in DJI\dji.pilot and not in the correct Android\data\dji.pilot\files
Those seem to be where people have had trouble with the channels hack since it came out in August.