Ive always been a fan of natural stratification....sow them in pots as normal but leave them outside for the wind, rain, frost, snow and sun get at them. Im sure they benefit more from being cold then warm then frozen then thawed out etc etc.

I then bring them into the warm in march time to get them germinated.

I have also just popped them into gritty compost and left outside in all weathers. They then went into the cold frame and left to their own devices. good germination rate too.

if you want to speed it up or cant leave them outside then pop them into damp compost and pop in the fridge for a couple of weeks. sow and keep frost free.

I find that you don't need to do anything special with tree paeony seeds. Plant a quarter of an inch deep (they are large seeds) in a pot of loam based compost and just leave outside in all weathers. They will sprout either next summer or the one after. In our garden they self-seed happily and weeding them out is an annual occupation.

Protect from rodents, they love those seeds.

Thanks -will pop some into pots and just have to wait and see!!