For this game you need a bowl or a basin and some treats that won’t dissolve in the water.
Suitable treats are for example pieces of dried chicken fillets, pieces of wiener or something like that (but not kibble).
I put like 10 centimeters (three to four inches) of water in the basin and then dropped the treats in. The pieces of wiener vanished in about five seconds.
If your dog doesn’t like water or he is scared to put his nose under the water you need to start easy. In the first time you can put only 2 to 3 centimeters (about an inch) of water in the basin with the treats.
If you like to make this game harder, you can put multiple tennisballs or some other obstacles in the basin with the water and the treats. In the pictures below I put small balloons and water balloons as obstacles into the basin. Those balloons slowed Miki considerably and it took Miki about two to three minutes to find all the treats.
And I’m sure you wanna play this game on the bathroom floor or maybe in the garden if you have that option, not on the living room floor.