[kranner]

> At it's most basic, it's about clearing your mind and practicing keeping it clear over some interval.

If there is one thing I have seen meditation teachers agree on, it is that meditation is not about clearing your mind. Your description of a Zen sitting practice does accommodate passing thoughts, so perhaps you mean something other than a no-thought state by a 'clear mind'?

It is sometimes possible to reach a state in which no thoughts arise for a long time (e.g. second and subsequent Jhana states) but that is quite rare for most meditators.