Warning, this question is about an unproven method. Do not follow these instruction to learn how to belay.
I am finding hard to find any good information about this topic. I know it is possible (but not recomended) to use a figure 8 plate as a belaying device, but couldn't find pictures of how is the device set up. Here is a pic of what i understand would be the correct configuration:
Is this way of belaying with a figure 8 plate alright? (Warning, experiment.)
I also came up with an idea of a different set up, which is shown here:
The nice thing about this one is that you always keep your brake hand below the device when giving slack. The bad thing is that the device goes away from the belayer when giving slack (but it returns with a single movement from the brake strand, also keeping the hand below the figure 8 plate). Here is a sequence of how that would work:
So, what's your opinion on using this second method for belaying? What are your feelings about testing this out and if tested and worked properly, are there any reasons not to use it?
---Edit--- The first method is partialy supported by this image from the Black Diamond Product Instructions - Super 8