I am the OP.
To clear things up, I was not trying for a rise out of the clerk. I've worked in service delivering pizzas, and been dealt with rudely. I always tried to go out of my way to accommodate customers, and to treat each request as legitimate, no matter how screwy it might be. The purchase was a last-minute, walking through the store to get to the car one. I saw the Cat Khrap in the case, and asked the nearest sales associate for it by name. No malice meant, no joke. Just a request that could have been worded better.
I didn't expect the attitude, or the reaction once the associate discovered the product existed, and was called Cat Khrap. I thought the exchange was funny in a tragic, groan "Oh no, they're both making a mistake" manner, so I posted it up. Not "Let's harass the associate", because harass is exactly what I did not do.
Those of you thinking I was harassing a wage slave, I wasn't. Merely buying an oddly-named product. No need to get on your Internet soapbox and impugn my morals or sense of humor.
For the many of you who haven't searched, the Cat Khrap is actually a sticky blue paste you apply to your eyewear with your finger. Comes in a little red container to make it easy to see. A little goes a long way. It works really well resisting fogging and fingerprints on my sunglasses. $6 well-spent at many sporting goods stores.