I grow French marigolds for the garden.  I read that the nematodes don't like them.  I plant them at the base of my tomatoes and throughout the garden.  It seems to be helping.  I check roots when I pull plants at the end of the season.  I have read it is added to some brands of layer feed for it's effect on yolk color.  I've found pumpkins, carrots, butternut squash and greens do this as well.
I am wimpy when it comes to hot peppers. 

I grow sweet bells and a couple cayenne.  I make pepper vinegar with cayenne.
I did grow an ornamental pepper in the past that sounds similar to the one you mentioned.  It was supposed to be very hot but I did not taste it. 

I thought it was very pretty and nothing bothered it. No deer or insects.