Cob: Fence and Brick

[Elizabeth Fox]

Hello again. I have two questions this time:

First, I want to build a fence out of the branches that have fallen from my
front yard trees.  I think I have a red oak and a london planetree - more
branches from the planetree than oak.  Question: What should I treat them
with before sticking in the ground, if anything?  I'm assuming the fence
will be temporary until we can afford iron (it's a city lot) but I would
like it to last at least 1 year.  What do you think?

Second, on the garden wall I'm building, I'd like to smash brick into a
paste for the final coat of plaster - to make it red.  Does anyone have any
experience with this?  Is brick made of red clay or is it a different
process that gives it the red color?

Your experience in this is greatly appreciated.
Beth