You need to also purchase a copy of Steve Midgett's book (if you have
not already). If you look carefully at Ian Ferguson's book, he is
using a hot isostatic press. This is a whole different ball game in
the making of mokume - shorter firing cycles are more appropriate to
this particular method.
Ochre is a powdered paint pigment available from most jewelry
suppliers as a solder-stop.
Best bet for mokume firing times is to make several experiments based
around the times and temps listed in Steve's book, and to take LOTS
of DETAILED notes to develop a system that works well for you.
Chris Ploof Studio