You can manually do it the same way. However, I did a test with OpenCL Mercury Playback vs CUDA Mercury Playback and they were both about the same.
Here is the process for premiere and after effects. Just change the path to be relevant for media encoder
Install Cuda for Mac OSX
1) Download and Install Cuda Drive for Mac: Around 20 MB
http://www.nvidia.com/object/mac-driver-archive.html
Premiere Pro CC
1) Need to run GPUSniffer. Open Terminal Window and copy and paste this command:
/Applications/Adobe\ Premiere\ Pro\ CC/Adobe\ Premiere\ Pro\ CC.app/Contents/GPUSniffer.app/Contents/MacOS/GPUSniffer
2) Open Terminal Window and copy and paste this command:
sudo nano /Applications/Adobe\ Premiere\ Pro\ CC/Adobe\ Premiere\ Pro\ CC.app/Contents/cuda_supported_cards.txt
After Effects CC
1) Need to run GPUSniffer. Open Terminal Window and copy and paste this command:
/Applications/Adobe\ After\ Effects\ CC/Adobe\ After\ Effects\ CC.app/Contents/GPUSniffer.app/Contents/MacOS/GPUSniffer
2) Open Terminal Window and copy and paste this command:
sudo nano /Applications/Adobe\ After\ Effects\ CC/Adobe\ After\ Effects\ CC.app/Contents/raytracer_supported_cards.txt
you just enter your card into the list and write out the file. The only difference between cs6 and cc is the file location path