Lumbering Laundry

Lumbering Laundry's first ability doesn't let you look at face-down spells you don't control on the stack.

The face-down spell has no mana cost and a mana value of 0. When you cast a face-down spell, put it on the stack face down so no other player knows what it is, and pay {3} to cast it. This is an alternative cost.

Any time you have priority, you may turn the face-down creature face up by revealing what its disguise cost is and paying that cost. This is a special action. It doesn't use the stack and can't be responded to. Only a face-down permanent can be turned face up this way; a face-down spell cannot.

Turning a permanent face up or face down doesn't change whether that permanent is tapped or untapped.

Once it has resolved, Lumbering Laundry's first ability lets you look at face-down creatures whenever you want until end of turn, even if you don't have priority. This action doesn't use the stack. Knowing what those cards are becomes part of the information you have access to, just like you can look at the cards in your hand. Once the turn ends, however, you can no longer look at those creatures.

If a face-down creature loses its abilities, it can't be turned face up with a disguise ability because it will no longer have a disguise ability (or a disguise cost) once face up.