Quotes make it only return results that contain exactly what’s in the quotes. All you need to do is put a string in your website that is unique to all indexed pages. Since there’s no length limit (well, google searches have a max length, but it’s pretty long), I expect that the vast majority of web pages will have some phrase you can use like this.

In theory, you could just search for the entire contents of a page in quotes and it’ll be the only thing that pops up unless another page is identical or contains an identical copy of the first page within it.

What? Just use an unique string that doesn’t give google results. When your site is inevitably crawled then you will be the one result

Be super indexed and write a phrase that is unique enough to eliminate 99.98% of other indexed sites when searched?