Well I can assure you they are not selling any Clown Knifes at our local Petsmart in Destin, FL. I've been trying to get one for months and I'm bidding on a 4.5" really nice looking one right now on AB for 8$ plus the s/h. Our LFS don't carry any of the insane stuff some people on here say their lfs carry, like RTC (not that I'd want one), spotted SD, Arowana, etc.
Also, I wasn't aware they needed specific food and only fed at night. I'm pretty sure it's not hazardous to get your CK on flakes or pellets. The one I'm bidding on now was raised from 1.5" on flakes and pellets and the seller says the CK eats good on that.