What's confusing you? (I'm trying to help, not being snarky)
If you want to invoke some Django-based logic at regular intervals without having to install Celery (and monitoring and a decent queue) you'll opt for a management command. The link you posted should help you out here. Invoking the script yourself or telling cron to invoke it for you shouldn't be hard if you know about cron.
With regards to Celery: I think the tutorial and docs are pretty clear on how to use it and how to set it up.
Thanks for your comment =) Nothing is confusing me there, but try to search for "django script cron" and you'll see people suggesting setting up urls to start the script, having an external script that import settings and many other complex things. The craziest thing I've seen (but probably useful for some cases) is to have the regular requests from google-bots invoke scripts... That's why I think it's a good thing to suggest managment commands when they're so easy and integrates nicely with your apps. Celery however is good for more complex usecases. I was merely making a suggestion for best-practise.
I imagine most of those icky suggestions are coming from people who used to run php on hosts with a lot of restrictions. You're right, this should definitely be a part of a best practices guide.
If you want to invoke some Django-based logic at regular intervals without having to install Celery (and monitoring and a decent queue) you'll opt for a management command. The link you posted should help you out here. Invoking the script yourself or telling cron to invoke it for you shouldn't be hard if you know about cron.
With regards to Celery: I think the tutorial and docs are pretty clear on how to use it and how to set it up.