Actually, shininess doesn't raise the chances of the offspring being shiny. Breeding pokemon from different regions does (ie. Japanese ditto + English pokemon). The ditto I have isn't shiny, but it it is Japanese, so if you breed it with a pokemon from a region other than Japan, then you'd have increased chances. Of course, if you breed a shiny with something from a different region, it would also have increased chances, but it isn't the shininess that affects it.
But yeah, if you trust the ditto you have/don't care, then just use it. Just thought I'd offer since you seemed skeptical of it.
