Actually what's the purpose of this code?
To get the device strings for pulse?
properties: device or device-name? 
(http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-pulsesrc.html)

I pushed in code to probe Linux and Windows for device strings for USB devices, perhaps you could do something similar?:
https://github.com/Freeseer/freeseer/commit/ac3197e26f93f911238ea2f731204cc992bac932#L0L116