Archiving the space is certainly a quick way to cut-off access, though it has some side effects you may or may not want. When you archive the space it will:
Remove all members from the space (including you)
Terminate all the content in the space
Prevent you from viewing anything in the space until it is unarchived
Will only be able to be unarchived by account owners, admins, or moderators
So I would only recommend this approach if it's the end of the semester, you have finished grading, and want to clean up the whole space because you are done with it.