How does The Wasting feature of the Walker in the Waste work exactly?

[Zephonim]

The Wasting (Su): On reaching 2nd level, you can transform a handful of dust or sand into a terrible disease. Once per day, you can blow sand into the face of a living opponent within 20 feet. Using this ability is a standard action that provokes attacks of opportunity. You can pick up dust from the ground as a move action or take it from a pouch as a free action. The opponent is entitled to a Reflex save (DC 10 + walker in the waste level + your Wis modifier) to avoid inhaling the dust. On a success, dust has no effect and drifts harmlessly to the ground. An opponent who fails this save contracts the wasting, a supernatural affliction that gradually mummifies victims."



Does the person infected instantly take the 1d4 Dex and Con damage(Source: https://i.imgur.com/QxZr6AM.png)? It says incubation is a day...

Would the best way to use this power be to use it on an enemy who is fleeing?

[Raenel]

If it doesn't explicitly say that the disease is changed, it works exactly the same as normal. Which sucks, but I'm sure some DMs out there will allow it to work instantly. Or at least faster. And as far as uses, you can also use it to interrogate someone.

NPC: "Nope, I ain't tellin yous nuttin. I ain'ts no snitch."
Player: Uses ability.
NPC: "What in da nine Ell's was that!?"
Player: "That, my good sir, was the wasting. You now have exactly 24 hours to tell me everything I want to know or you will get to feel the joy of becoming a mummy as your flesh slowly dries out and cracks, leaving you with nothing but pain as you shrivel up and die. So, how loose does your tongue feel?"

[Fouredged Sword]

It's a thing designed to wipe out towns. Go (greater) invisible and blow dust into some faces and watch the whole slowly wither and die out. It's a stealth attack.

It's more of an evil NPC skill, but the whole class is kinda an evil NPC class. This is just not a skill designed for combat. This is a skill that allows a 3rd level character with a good bluff modifier to wipe out a town.