Hi, I too have started milkweed seeds and all are growing well, just waiting for spring (may/june around here). While I don't know if they will be big enough to provide much food this year, I'm hoping that in years to come I'll have millions of plants! At any rate, despite all of the warnings about them being difficult to germinate, mine all sprouted within a few days. Some are the butterfly weed variety, but most are an unknown variety ordered through livemonarch.com. All they will tell me is that they are the northern variety! I wrote them to ask specifically what they are but it's a big secret I guess. Still waiting for my common milkweed seeds to arrive, and hopefully they will sprout easily as well.
I used the baggy method for starting the seeds. Using this method you mist a coffee filter with water, arrange the seeds, fold the filter up, and put it in a ziplock baggie. I didn't refrigerate them or anything prior to bagging them. I did however soak a bunch of them for 24 hours, some sank, and some stayed floating (with many seeds this will tell you if they are viable.) Then I put them in separate baggies, but germination was about 90% within 4 or 5 days for both. Others I didn't soak at all and they still germinated. Once rootlets are started you pluck them out and put them in flats to grow up.
Anyway, that's my experience so far,