My go to method for germinating cannabis seeds has always been putting the seeds straight into paper towel wet with un PH'd tap water and set on a plastic plate (I find they are warmer than porcelain or ceramic plates)
Sometimes I cover the plate with another plate to block the light out, but when using a heating pad it can dry out the paper towel much quicker as the hot water likes to rise quickly. So if or when using this method make sure to keep an eye on your paper towel so it doesn't dry out!! This part is very crucial^
Thanks for looking and enjoy the grow!