Preheat oven to 400 degrees F (200 degrees C). Spray mini-muffin tins with nonstick cooking spray.
In a medium bowl, stir together crabmeat, green onion, mayonnaise, curry powder, salt, lemon juice, and Swiss cheese. Use kitchen scissors to trim off corners of individual wonton skins; place trimmed skins in wells of mini-muffin tins. Spoon about 1 tablespoon crabmeat mixture into each wonton cup. Top each with a slice of water chestnut.
Bake in preheated oven about 12 minutes, or until puffed and browned.