Yes orange juice breaks down the hard coating. nicking is just chipping the hard surface so moisture can get in. I use a dremmel tool with a cut-off wheel and just skim the surface of the seed, just enough to permeate the shell.

If the passiflora seeds have been dried for any length of time a soaking in a mild acid solution like OJ will help remove germination inhibitors but there is absolutely no reason to nick a passie seed coat. The seed coat is permeable to air.

I planted several seeds and got no germination. After digging and finding only one seed I scarified it and it germinated. Maybe it was coincidence but I will scarify all my passie seeds in the future.