MacOS – Show hidden files in SELECT folder only

It worked for me in 10.9. You should be using -bool TRUE (not just TRUE), although it worked for me either way. Also, are you running it as two commands (killall Finder is a second command)? The only other thing I can think of is that cfprefsd might have the old setting (or lack therof) cached, so you may have to shut it down it first. If I understand the setup right, that shouldn't be necessary, but just in case:

killall cfprefsd
defaults write com.apple.finder AppleShowAllFiles -bool TRUE
killall Finder

I think Finder is out...

Mac OS X does not show you companion files unless you use Terminal, and sometimes not even then. (It shows invisible files rather easily, but to Mac OS X, both "MyFile" and "._MyFile" are two parts of the same file, and it doesn't normally return two directory entries for one file.) You only see these companion files on non-HFS disks that you move to other operating systems.

http://lists.apple.com/archives/applescript-users/2006/Jun/msg00180.html

So, the only Options I see is using VCP7, or Paralles, etc., to have a pseodo way to see them in Finder, or....

Write a script to list those files in a window & maybe link them back the the real ._ files.