I read watering an inch daily would help lower the damage.

Lots of water daily and hopefully that will wash it out. But dont water in the evening as this will encourage fungus and then you will have another problem too! Good luck.

Perhaps someone more knowledgable can confirm, but if the grass is already yellowed, wouldn't it be too late to "rinse out" the fertilizer with extended watering?

You should water not to rinse out the burn, once the blades are burnt, they're burnt, but to encourage the lawn to grow. Hopefully your grass has enough carbohydrate reserves to regenerate the blades, and frequent watering will encourage growth. Of course you will probably loose some grass, but you want to make conditions as favorable as possible so whatever is still alive will continue to be alive.