Speaker Slip Covers

Does anyone know where I can shop for slip covers (that's the best description I can think of calling them) for speakers?  I rescued 2 kittens about a year ago, and since then I have rearranged the stereo systems in 3 of my listening rooms.  So far (fingers crossed), they have shown no interest in my speaker grills.  However, as a retired Insurance Executive, I like to minimize my risks.  I recently bought a pair of KLH Model 5's, and I'm looking for a cover that would slip over the speakers when not being used -- think of a pillow case except designed for speakers.

I have searched online using several search parameters, but I've only found one site that lists covers for KLH Model 5's (you can get them in linen, cotton, or other fabrics).  I'm also wanting covers for a set of Polk Audio Model 10's and a set of Klipsch Forte II's.  I would appreciate any help on where others may have bought slip covers or what others have used to cover the speakers and protect them from pets, dust, etc.  Thanks in advance.

Allen