Be sure you install the latest Stand-Alone Addon Manager (you should have received an update notification for it), because the August 25th update should have fixed a remaining problem of airports with 0 parkings not correctly excluded:
http://www.fsdreamteam.com/couatl_liveupdate_notes.htmlUpdate date: 25-Aug-2016 10:47 PM
Fixed a problem detecting some airports with 0 parkings, which affected some 3rd party sceneries like Aerosoft Alta X.
Also, from your message, it doesn't seem you understood the problem, or how the airport visibility command (which shouldn't be needed anymore with the current version) works.
First, using the airport_visibility_sbgl = 0, you tried to exclude an airport with the SBGL ICAO. So, if this is the airport you are flying from, no wonder it doesn't work: YOU told GSX to exclude it!!
The airport_visibility command, as explained in the manual, should be used only to exclude AUXILIARY airports with DIFFERENT (usually fictionary) ICAO codes, used by some developers to represents seaplane bases, helipads, military bases inside the main airport, etc.
It cannot be used to auto-magically "fix any conflicts", of two airports sharing the same ICAO, if this is what your situation is.
If two airports share the same ICAO, the only chance to have GSX working on the "correct" one, is the other (or others) don't have ANY parkings. This is done automatically by GSX, and it's supposed to work with the latest version.
Also, I noticed you made a separate text file with the airport_visibility_sbgl = 0 line only, in the GSX custom airports folder. This is NOT how that line works, and it's not how the GSX manual explains.
As the GSX manual explains, you must add a line for every airport you want to exclude,
under the [GSX] section of the %APPDATA%\Virtuali\Couatladdons.INI file, if you have several auxiliary airports to exclude, you will have several airport_visibility lines, but ALL in the same Couatladdons.INI file!
This leads me to believe, you ALSO have such lines in the Couatladdons.INI, but you are creating unnecessary files too, that don't have any effect. Only the lines under the [GSX] section in the Couatladdons.INI will be used by GSX.
