[General] "thanks but no thanks" means?

[EngFan]

Hi Guys,

I'd like to know the meaning of "thanks but no thanks" and how to properly use it? Please advise.

EngFan

 

[Munch]

Thank you for offering but I decline.

• Thanks: Thank for offering to do that.
• but: but
• no thanks: I don't want that.

I don't think it is a good phrase to use in conversation, unless you are really confident. It can sound glib or even rude.