xfsettingsd and gtk2 themes

[hl.xfce]

Hi

I want to set a GTK2-theme per Application (e.g. see [1]) . Normally I'd 
do this with "GTK2_RC_FILES=/usr/share/theme/.../gtk-2.0/gtkrc ./myapp".

But while using xfwm4 / xfsettingsd (?), my GTK2_RC_FILES-Variable seems 
to get (at least partly) overwritten - i cannot change the gtk engine.  
Killing the xfsettings-process fixed the problem temporay.

Can I block theme settings from xfsettingsd per application?
Can I patch a sources of a gtk-application to ignore theme from xfsettingsd?


Thanks,

hl

[1] 
http://urukrama.wordpress.com/2008/07/13/setting-a-custom-gtk-theme-for-specific-applications/