I've tried it once - as a fun experiment - but I thought it was a little ambiguous :p
I asked to see a real cat of a specific colour. And on that day itself I did see one, but it was in a picture, lol... Perhaps some people might say that it worked in this case. But I saw it as just a co-indence... I have plenty of questions about the law of attraction itself.
Then again, once is probably not enough, so maybe I should try it more often - Besides, drawing sigils is fun (although you're supposed to forget the image or burn it to perform sigil magic), and that's what interested me in the first place
D