Removing background with a doctor's precision

After hours and hours of trying to remove the green screen background from my photo session pictures using the hit-and-try method I managed to develop the procedure that seems to work. It also seems to be very complicated but I really cannot think of any other way to do it. Once I've done few pics I think it still is laborious and time-consuming but also doable. 

This is the procedure:

1. Open the picture in AfterEffects, shorten the timeline to 1 frame only and remove background using Effects-Keying-Keylight. Change the screen color to white, adjust picture grain and balance.
   
2. Export the image as png file (not jpeg, for some reason if exported as jpeg the background remains black while if exported as png the background turns light grey). 
   
3. Open file in preview (again if you simply open it in Photoshop the background goes black again) and save as jpeg.
   
4. Then the jpeg file is ready to be edited in Photoshop. Remove the background completely using magic or quick selection tool. 
   
5. Once the background is transparent save as psd file and jpeg file (you will need to overwrite the previous jpeg picture if saved with the same name - it is not needed anymore and saving all format off the same picture with the same name will help to keep the files organized).