19.—(1) No person shall drill a shot hole or any part thereof with a drill of which the diameter does not exceed by at least one eighth of an inch the diameter of any cartridge to be inserted in that shot hole.
(2) No person shall for the purpose of testing, charging or stemming any shot hole use any tool other than a tool, made wholly of wood, suitable for the purpose.
20.—(1) No person shall begin to charge any shot hole unless it is thoroughly cleaned out.
(2) No person shall use compressed air to clean out any shot hole unless he ensures that the giving off of any dust is minimised.