I e-mailed GB about using their Axestone. This was the reply:
Our sharpening products is so new that our covers donīt have the English
translation yet. Here is the instructions in English.
A good cutting edge can be maintained much longer if you exercise good
judgment when using your axe. Information about axes and their use can be
found in The Axe Book which can be ordered from www.gransfors.com
Sharpening your axe
Make sure the axe blade is free of dirt and resin before you begin,
otherwise the area sharpened will be filled in and the "bite" will be lost.
In case of smaller dings or normal wear the coarse side of the Axe Stone
should be used. The stone is normally used wet but can also be used dry.
Using light pressure, work in circular motions towards or away from the
edge. The Axe Stone should be rotated occasionally to ensure even wear.
Metal shavings should be cleared from the stone by blowing on it, brushing,
or rinsing it off with running water. Finally, with the help of the fine
side of the Axe Stone the proper edge can be restored.
Change sides and sharpening angles often until the edge has a smooth and
even surface. If the edge becomes too thin and fragile you can work against
the bit, using a circular motion. This will help achieve a wider cutting
angle and stronger edge.
When finished, rinse the Axe Stone with water and dry with a soft rag.
I thought it might be of use/interest to others.