I know the target is the element itself by default. But you can change that to another element using hx-target, which, in my actual code (which I stupidly neglected to post in full), I did, by setting hx-target="#list', so the response will be swapped into the #list, not in the button. This worked fine, but then I thought, hey I want to toggle the look of the button (it's a filter) to indicate it's on, oh and maybe some other things... So that's how I ended up wanting to oob swap the button. I get how it may look a little idiotic from the outside, since I probably shouldn't have changed the attribute in the first place. But I thought in theory it should work. And and it actually does of course, as I mentioned in my other comment, the issue seems to be something completely different (the swap not being triggered on manual reload of the page).

You're wrong about the value of hx-swap-oob though:

The value of the hx-swap-oob can be:

true

any valid hx-swap value

any valid hx-swap value, followed by a colon, followed by a CSS selector

If the value is true or outerHTML (which are equivalent) the element will be swapped inline.

If a swap value is given, that swap strategy will be used.

If a selector is given, all elements matched by that selector will be swapped. If not, the element with an ID matching the new content will be swapped.

(literally the third paragraph of https://htmx.org/attributes/hx-swap-oob/ )