No I did not buy from that pet shop, I bought from US Amazon. When I did my research a few months ago, this was the only place I could find in HK that sells food grade DE. As I stated in my previous post, I have not used this brand I could not say it is good or no good. Which is why I suggest doing some additional research before you make your decision.
I bought from US but I used the powder in Hong Kong. You cannot use your hand to dust the powder because the powder is very fine. I bought a Squeezable soy sauce plastic container with pointy mouth from $10 shop to apply the DE powder.
I have called the pet shop asking about DE, they said that it is for 驅虱 not for 滅虱. However, you have tried and it works, I will buy one and try and hope it works.