You've got it, If you leave it in plastic you should mist it with water regularily, or what I find easier is to wet an old towel and drape it around what I've made,then put it in a plastic bag that should stay damp for several days.Or you may submerse it depending on how large it is of course.
Cindy

Ah the wet towel is a good and easy idea, thank you very much. I went out and did that.

So while it's kept damp, does it retain its slightly fragile status much like when it's newly unmoulded?

Or does it gradually strengthen even while damp/wet as the days/weeks progress?

It gradually strengthens, it will cure and should be good at the 30 day mark. The keeping it wet slows down the cure and will give you a stronger end result.

I allow to cure for 1 to 2 weeks.
It will gain the most strenth if allowed to cure for 1 week, a little more strenght after 2 weeks.
I typically cant wait more than that.
I beleive it is also inportant that you dont mix it too wet, but rather on the damp side, I beleive this will help with the longevity of the container.