The Set-VMCPSettings function is not an official function afaik, but a community contribution (from 2015).
You will have to give a bit more info than just " it doesn't work".
Do you see any settings being changed in the cluster when you check via the WebClient?
Do you get any error messages?
There are currently no official PowerCLI cmdlets for that functionality, but you can call, like that community function, the API method directly from PowerCLI.