I think 6 weeks is a little short for the moist cold...my own will normally begin germinating at 8-10 weeks chill - germination will continue into the 12th week.

Did your seeds get the moist warm period before you began the chill?

I have my seeds outdoors but I suspect our Z8s are quite different. My seed pots are being exposed to days in the 50's, nights 40F or below and that will most likely continue through the end of this month with only a little variation to the daytime temps.

I think they like to be cool, under fifty degrees, so I think it would be safer for you to keep them in the refrigerator ... and when a few sprout and you have to move the pot out into the light, I think you might be best off to find a cool spot outside and bury the pot to keep it cool.

They still did not germinate at all... I usually go with the Thomson and Morgan instructions because they seem to be pretty reliable. However, I am not sure in the case of Hellebores. They keep changing the time you have to leave the seeds in fridge.

For example, when I purchased the seeds in January they wrote I should keep the seeds in the refrigerator for 6 weeks. Now they changed their instructions and they say they should stay 3 months (or 12 weeks).

Well, my seeds are at their 10th week and they have not germinated yet.