Pepper Joe recommended to soaking Carolina Reaper seed in warm water about. 24 hours before putting them in the soil or other medium.
I usually never soak my seeds then I use Root Riot cubes instead of soil and a heat mat so I can keep a temp of around 28 degrees. These small cubes made of an organic sponge materials are probably the best I've tried so leads in it only took 7 days for all 5 Carolina Reaper seeds to germinate.
When the supply of these seeds were not so great so I did not buy as many as I wanted to without max 20 seeds were the man got order so I have saved some to germinate at a later time.
Now, in all cases, all 5 the seed germinated, and looked up from the cubes so now I lower the heat to about. 22 – 25 degrees to the first character leaves turns out. Then it becomes to school them in a small plant pot with soil and a cooler temperature on ca 18 degrees.
PS. I have a lot of other interesting strong chili varieties that also begins to look up from the cubes!