My stove doesn’t have an ashpan, but it has strong draft. That draft can work like a nice vacuum around the door.
By dumb luck, one of the Pilgrim ash pans happens to line up very nearly with the lip around the door, so I line it up under that to empty it. If I do this when the stove is hot, and just crack the lid right in front of the door to load the ashes, any stray ashes are sucked up the chimney.
If you can find an ashpan that lines up nicely with your door and use the lid as a baffle to help block stray ash, your stove draft can be a big help and it will avoid the need for using a vacuum.
Still, I’m sure an ash vac would be the best solution of all…
-Colin