Share a desktop that only has the demo on it

Every screen-share tool has a "share this window" option, because the rest of your desktop is a liability: the Slack popup, the tab bar, the notes you wrote about this customer.

Hoody containers address displays by number: display-1, display-2, each its own URL, up to six figures of them. So the demo runs on its own display, and the URL you send the customer is that display's. Your editor, your chat, your notes live on display 1, at a URL nobody outside the team has. There's no window picker and no discipline required: the audience's link renders a desktop on which your other windows don't exist.

Nothing to accidentally alt-tab into.

You don't share a window. You share a computer that only has that window.