QuickPic sees the pictures on my extSDcard fine. I'm not sure why it won't show them for you.
I used QuickPic to hide folders and they disappeared out of the stock gallery too. The internal folders disappeared straight away, and the to get it to rescan the microSD I unmounted it and then mounted it again.
Just make sure you use hide not exclude.
What hide does is put a blank file called .nomedia in the folder. This stops photo, video or music apps scanning that folder. You can still browse that folder to access the media.