After reading several articles on ebonizing I decided to stack the odds in my favour by using the two-part process outlined in the article in Popular Woodworking. The article indicates to do an initial preparation of your wood using a bark tea made from Quebracho bark. This adds a lot of extra tannis to the wood which are what later react with the vinegar / steel solution. This seemed logical given using just the vinegar and steel solution works best on woods with high tannin content such as oak and walnut.
So I ordered two pounds of Bark tea from Van Dyke's (the minimum order).
Next I bought a litre of Heinz vinegar, got a used plastic Folgers coffee container and some #0000 steel wool from Lee Valley. It is advertised as being completely free of oil so I just tore off a good section and put it in the vinegar.
I did this all a few days ago as it will take time for the steel wool to dissolve and the bark tea to arrive.