You have been given some very good advice here. The only thing I can add at this point is that the main advantage of a barber hone is the size which makes it very convenient and the ease of use, use it dry, with water, or lather.
With any hone the one thing you want to avoid is where the sides are "high" ( center is dished). That is about the only time lapping would be required for a barber hone. It can be kept clean with rubbing stones, nylon scrub pads, brush etc.
Just my $.02, :)