I use a
lightweight inflatable pillow from Decathlon, placed inside the stuff sack for my sleeping bag (which has a fleece lining for the purpose). If you get the pressure right, it's actually a more comfortable shape than the Ajungilak, and will happily fit within the hood of the sleeping bag (the Ajungilak is a bit wide). It's also lighter, on the slightly dubious assumption that you'd be carrying the stuff sack anyway.
I have also used it on its own, and while the hard to describe fuzzy plastic surface is not as comfy as fleece, it's fine for a S24O.
In the absence of a convenient fleecy stuff sack, Ajungilak wins on comfort, IMHO.
The stuff sack full of clothes approach also works, but only if you're not already wearing them to sleep or leaving them open to dry. I sometimes do this with a non-fleecy stuff sack to elevate my knee.