To make this work:

Archive the Payload folder to "Swisscom_ch.zip"

Then rename it to "Swisscom_ch.ipcc"

Alt-Click "Check for updates" in itunes and select the said ipcc file
If it's grayed out, make sure it's ipcc and not zip (use terminal)

Restart your iPhone and you should find it under Settings -> General -> Networking -> Tethering

Enjoy.