WE have a solid fuel 'shipmate' bulkhead mounted stove. This thing came w/the boat as we bought her last year. I have had maybe 5-6 fires in the thing so far. Burning charcoal. Lighting the fire with knot lighter. Great heat and heats the boat, but must be tended to every couple hours. Messy, yes, as far as ashes. Basically when there is a fire going someone has to tend to it, just like sailing, the boat doesn't sail itself.
Oh, And another thing about solid fuel, at start up the whole cabin can fill w/smoke until sufficient draft by the heat of the fire will suk it out!