That's basically it, but it's also part of keeping your exit habits/rituals low key. I tend to get things ready either a bit at a time or while the dogs are in the garden or something so they don't hover about watching me get my stuff together.
About 10-15 minutes before it's time to leave I put them in their beds and tell them to settle (they've both been conditioned to the settle cue and I do this regularly throughout the day when I'm not leaving as well). Then I might go and sit on the sofa and watch tv or read for 10 minutes or so or sometimes perhaps do the dishes or have a quick tidy round (it needs to be different things each time really) before quietly going in, putting down their kongs (in the pup's case he's in his crate so I just open the door and pop his kongs in) then leave without saying a word. When I was working on Lurcherboy's SA I would do this whole process, then go straight back in, remove kong and go and sit down again or make myself a cuppa, leaving it different lengths of time before going back in, so he was never sure if I was actually going out or just leaving him for a few seconds or minutes.
When we return home, for example after the school run, as my dogs are in the kitchen, I deal with the dcs, bags, coats, shoes, book-bags etc - read any school letters and get the dcs changed out of uniforms before I go into the dogs. Then I go in the kitchen, say a calm 'hi guys' and proceed to make the dcs snacks. The dogs aren't expecting a huge hullabaloo of a greeting, so tend to carry on chomping they're kongs and when the dcs sit down for their snack I give the dogs a fuss and say a proper, but calm hello.
Both dogs seem genuinely pleased to see their kongs and can't wait for me to go so they can get stuck into them. I record them on a dictaphone to see if they're quiet. Lurcherboy is now happily settled for just under two hours, then he starts whining, but Pip starts whingeing, then yelling as soon as he's scoffed his kongs and treat toys - so either just under or just over an hour, depending on how clever he is at unstuffing his kongs.
It's been a very long, slow process with Lurcherboy, despite him only starting to show signs of SA after we lost our other dog to cancer back in April. He is definitely much more relaxed now, but if they tested his cortisol levels, I'd say they almost definitely increase and continue to increase dramatically as soon as he finishes his kong. When I first started the programme he was too stressed to eat when I wasn't home and would flood the kitchen floor with drool - so he's come a very long way, but it's been very hard work and extremely life consuming.