I want a customer to be able to service a page of his own in his webb made by me with Muse. Is that possible?
Let me try elaborating your query and please correct if am wrong.
By customer you mean client, and you want them to be able to modify their website designed by you once it is published.
If this is what you are looking for then I would like to introduce our special InBrowser editing service - Edit Adobe Muse site content from a browser.
Please let us know if this what you queried for!