"Set this site as your home page" – how difficult?

My client wants to add a “set this page as your home page” feature on her site, but what I’ve read is that you can add a javascript for it but it works in Internet Explorer only, but can be modified to work in Firefox if you make the user stop and use a code to access Firefox and change a setting. I don’t want to add “hoops to jump through”.

What I read was three, four, six, and [amazingly “ancient”) twelve years old. I have a hard time believing this is that difficult to do.

I’ve looked for plug-ins, and they don’t seem to be obvious.

So I’m wondering, is this impossible to do without “hoops”?