I did an experiment last year where I kept the seeds in little viles on top of cotton just to see this exact thing. I used compost tea, coffee, water, and about 10 other things if I remember correctly. The end result? in sterile conditions, nothing made a difference as the the germination rate. They were all about the same.
However, if there is something in your soil that is hindering germination, then an additive may help. But to make this effective for you, you'd have to isolate the culprit and find out what type of additive would neutralize it.
USDA Zone 7a, Sunset Zone 32.
Failure is only a fact when you give up.