I'm also having the same difficulties on Option 6 (Painkillers)
I try using the Option 6 (Painkillers) function, but it doesn't seem to do anything for me. It announced ACTIVATED, but my painkiller number never change also!
Rockstar Games decided to deliver a different game version to germany after the USK (like ESRB/PEGI) complained about the possibility to harm pedestrians.
I wonder if it could be possible for german users to provide the needed offsets from such modified versions to CH.