Don't know in what your zone you are. I'm in zone 6 and last year I winter sowed them with great succes. I also sowed them indoors, with a little bit less succes, but still I was succesful. I noticed that the wintersown ones are stronger.
All the seeds I sowed were from trades. There were some not germinating at all, but that must have been bad seeds, since they were germinated all in the same conditions.
The succesfull ones had a germination rate between 50% and 80%
I'm no expert, but have read several places to let them dry for a day or two and refrigerate them for 2 weeks. My only experience is with about a dozen seeds that I collected last year and were refrigerated for a few months. I had 90- 100% germination on those.