So disingenuously humor the client for a day or two before shooting their idea. Honestly, if I was your client and this happened a few times, I would start to wonder why you lack the expertise to immediately know ideas won't work.
The client is not talking for the sake of talking.
They are expressing a desire, a need or a want
Almost always you can dig down to their motivation and get a better idea of what they are _really_ after, even if the clients proposed "solution" is technically impossible.
I'm not sure if you understood me. I don't think it's a good idea humor your clients. In fact, I think if could hurt you if they ever get wise to you bullshit.
