You should really keep the hot coals and just rake the ash into the ash pan as no need to throw away good heat.
I mentioned in an earlier post the drop holes work great as the nature of the stove is such that the draw of the stove keeps the ash dust from coming out of the stove while your raking the ash thru the drop hole. Even if the stove isnt that hot there is still some suction pulling stuff up the flue, especially light weight ash dust. The size of the drop hole shouldnt be an issue unless your trying to shove big chunks of coals down it.
I have tried to shovel out ash to a bucket, the speed at which I have to do it, to not get the ash a flying around is so slow it makes the process take for ever. I could make two trips out side and dump a small ash pan and still save time from slowly shoveling out 1 shovel full at a time very slowly not to cause a big dust cloud as then I am dusting the whole place to keep my wife from getting PO'ed.