From Webkinz Insider Wiki
How Do I Play It?
You can go to Daily Activities and in the right hand corner you should see an advertisment for it, click on it, then it will bring you to the game.
When Can I play?
You can play anytime of the day, but you can only play each game once a day.For example, you can play 1 ball game, 2 ball game, 3 ball game all in one day. But, you can't play a 2 ball game three times in one day.
When you first click on it, it will automanically bring you to the one ball game. Once at it, just click on the big ball mixer-type thing and it shows you the number that was called. If you have it on your board, it automanically covers it, if you don't have it, nothing gets covered. Once, your done playing one ball game, you can then proceed to play the two ball game and three ball game by clicking on them below the "Shout Bingoz" button. If you do get bingoz, click the "Shout Bingoz" button and you win! If someone wins before you, your board re-sets.
It is possible to obtain Wacky Bingoz Extra Ball Coupons. If you do receive or get one, once you play Wacky's Bingoz it will appear under coupons to the left. If you want to use one, click it, and an extra ball will be in play.