I've always had good results with the 'One-Man brake bleeding' kits. There's many variations, this one is just the first that came up. But they included a one-way valve to stop air re-entering during bleeding. As long as the other end is always under topped-up fluid, you can go all day removing any pesky bubbles, moving from corner to corner.
https://www.peterstevens.com.au/oxfo...bleed-kit.html