MTG can someone explain how does ripple exactly work?

You can only play another Surging Dementia if it's revealed, not any sorcery card, because the effect only lets you play the card if it has the same name. The point of playing this card if it's the only Surging Dementia in your deck is having a player discard a card. It stops when you reveal cards and there are no Surging Dementia revealed. Since it stops when you reveal no Surging Dementia, you can't just keep going through your whole deck unless every 4 cards you reveal, there's a Surging Dementia. You can't choose whether or not to use ripple, because it doesn't say "you may."