How can I remove ink stains from IOTV?

Those only work on organic stains, ink is an inorganic stain so you need to use a solvent. You have to start with weaker solvents first because nylon is synthetic and will melt from a strong solvent.

You need to blot, not scrub. Try these solvents in order of weakest to strongest:
Isopropyl alcohol 90%
Acetone/Nail polish remover
Goo Gone
Goof Off

Try Goof Off.

Amway LOC takes ink out of clothes. Melaleuca also has a product but you'd have to check into that one, but it works. I'd go with the LOC first because I know it won't affect the OTV negatively.