Yes, it is, sorry for not looking into this more thoroughly. I was under the impression that I would need to collect sources and compile them, while in fact it is possible to make use of the Ubuntu packages.

Here is a brief how-to/demo in case anybody is searching for this in the future:

~$ mkdir dicts
~$ cd dicts
~$ aptitude download myspell-de-de
~$ ar x myspell-de-de-<VERSION>.deb
~$ tar -xf data.tar.gz
~$ cd ./usr/share/myspell/dicts/
~$ python
>>> import enchant
>>> d = enchant.dict("de-DE")
...
enchant.errors.DictNotFoundError: Dictionary for language 'de-DE' could not be found
>>> enchant.set_param("enchant.myspell.dictionary.path", ".")
>>> d = enchant.Dict("de-DE")
>>> d.check("Erfolg")
True

The remaining files from the .deb package can be removed afterwards. However, I found that the usr/share/... structure needs to stay the way it is.