My friend, Susan, and I disagree on just about everything except home design — until now. Yes, I understand that an 8- by10-foot area rug would have worked better size-wise in my 10 by 13 living room.

Enter the washable rug. Ruggable, Surya and other companies promise the ability to deep-clean your area rugs by simply tossing them in your washing machine. Sounds great, right? But does it work? The ...