That's why I am asking. Last 2 years i have seen a lot of fish caught with yarn on the hook or with some sort of pink hoochie/squid over the body of the spinner. I rarely get out fished down here but the ones that use the yarn and hoochies catch a lot more than people not using them. It isn't really a fair comparison though because these same people can catch fish without doing it if they don't have yarn with them.
I am going to try it this year, getting ready to tie some yarn to some Siwash hooks so I have them. If i don't get a bite and fish are moving I will use a yarn hook and try to see if it actualy makes a difference or not.
As for other fish, a squirrel dressed hook outfishes a plain treble on a spinner hands down for me for trout, maybe close to 10:1. Single hooks, no difference that I have ever noticed unless oyu count adding a worm to the hook as dressing it then it makes a huge one.