Success in removing unwanted ink stains always depends on several factors, first and foremost of course on the type of material stained. Unfortunately, there is no patent remedy.
In the case of clothing, it can be helpful to pre-treat it to dissolve the ink and only then wash it. Gall soap or stain spray are suitable for pre-treatment. Some customers have reported that spraying on hairspray dissolves the ink and the stains can be washed out easily afterwards.