What is an expression or idiom for something old that is sold or offered in a deceptive way as something new or innovative? Ideally, the specific instance of the thing is not what is old or new, but the design or concept, though I'd take either. Also, the object may be perfectly effective, just already very well known, possibly already owned.
There exist related common expressions such as:
- "snakeoil" for something completely ineffective, but deceptively sold as an effective remedy.
- "silver bullet" for something that is proposed to be a simple total solution to a particular difficult problem. Although usually used in the phrase "there are no silver bullets", I believe just the words "silver bullet" would be understood to identify a false solution even if the speaker did not qualify this with the "there are no".
But I'm looking for something that a charlatan or dishonest sales person is perhaps calling by a different name or repackaging or otherwise claiming is totally new and different. Possibly, but not necessarily, specifically replacing an instance of the thing already in your possession.
"Super Special Sea Salt" is obviously not a established idiom, but kind of illustrates the ideal properties of the target idiom: it actually is what it says it is (mostly), and what you already have in your kitchen is virtually indistinguishable from the proffered supposedly superior variety (if not exactly the same; I believe before it was trendy to buy "sea salt" quite a lot of table salt already was produced from evaporated sea water).