Setting up a starter environment with a pre-used test instance

Summary:

I am prepping for using the starter environment. A pre-requisite for this is that its a clean environment. On preparation documentation there are the options for having a clean non prod, or having a populated non prod (with a clean prod) and doing an P2T.

For us we have been live for a number of years and have a spare environment which I want to use rather than buying yet another environment. What I was interested in is if anyone has tried to wipe/delete an instance and re-create it as an empty environment? I can see the big red delete button but the online documentation is not great of consequences, e.g. is to for decommissioning and environment only or can you re-provision after.