Removes all Amazon saved for later items on the cart page. It will only remove visible items. You might want to scroll first to make more items visible. To use paste code in developer console (Ctrl+Shift+J or Cmd+Opt+J in Chrome) then press enter.

deleteAmazonSavedItems.js

function deleteSavedItems() {
	var query = document.querySelectorAll("#sc-saved-cart input[value=Delete]")
	if (query.length) {
		query[0].click();
	}
	if (query.length > 1) {
		setTimeout(deleteSavedItems,100);
	}
	else {
		console.log('Finished');
	}
}
deleteSavedItems();

None of the above worked for me unfortunately, but after some iteration, I was able to get it to work for me:

async function deleteAllSavedItems() {
  while (true) {
    const deleteButtons = document.querySelectorAll('input[data-action="delete-saved"]');
    if (deleteButtons.length === 0) {
      console.log("No more saved items to delete.");
      break;
    }

    deleteButtons[0].click();
    console.log("Deleted one saved item, remaining:", deleteButtons.length - 1);

    await new Promise(resolve => setTimeout(resolve, 2000));
  }
}

deleteAllSavedItems();

Maybe Amazon updated their HTML, so the other approaches didn't work.