How do you get flair pen ink out of 100% cotton clothing? I have used shout and cold water.
Try spraying the ink with hairspray before washing. Also, you can try Carbona brand spot remover. They make several formulas. Look for the one for ink and crayon. I find it at Walmart on the Laundry detergent aisle.
Some things you may try (seperately, of course). One, hairspray. It gets out regular ink, try it on Flair. Also, try GOOP. I think it may be found in the automotive section. It is a handcleaner, but can be used for laundry stains. GOOP has gotten out 98% of my fresh stains. Make up, blood, juice, even formula from baby's spitting up. You may also try RID's (or is it RIT??) laundry whitener. However, you you have already put the garment in the dryer, it will be a lot harder to get rid of the stain.
I have had luck with rubbing alcohol. Hope it works for you.