Actually it works very well, I have used shark , sturgeon and halibut with great success, lay it flat after skinning let dry and thin to desired thickness , I use a belt sander to get to the thickness I like.
Fish skin is a very tough durable backing that in my opinion is much tougher than rawhide.
Helps to rinse well with Dawn dish soap to remove any oils.
Yes on shark or any other rough skin make sure you sand the skin and coat several times to remove the roughness especially around the top limb where the string would rub when stringing and unstringing.