The short version
What this module is for
Every serious shop works on a copy. And every copy raises the same three problems: it gets mistaken for production, it still carries production's domain throughout its database, and it holds real customers' personal data on a less protected environment. This module handles all three, from a single screen.
Flag it
A tinted back-office banner and a badge on the public site: you always know where you are.
Rewrite it
List the columns holding the production URL, then rewrite them column by column, serialised values included.
Anonymise it
Names, e-mails, addresses, messages and IP addresses replaced in batches, across the database or for one customer.
This module belongs on a staging site, not on production. Its write operations cannot be undone. Its safeguards refuse to run on a shop open to the public, but they assume you know which environment you are on.