Finger leather will stick with super glue gel. At least my brown one does. This one didn't bleed (slime) much. I do the gluing outside the tank. Pat the rock dry, pat the wound dry and apply the glue to the rock. Hold firmly for 15 seconds and put back in the water.
I have some green tree that no glue will hold. It holds for a couple days then the coral retracts (rejects) and comes loose. I found a rubber band wound firmly, not tight, just enough to hold the frag to the rock in the desired position works good. They attach in a couple weeks with this method.
I do stonies with underwater epoxy. Again, I do the gluing outside the tank. I have done acropora by simply laying a small frag in a rock crevice. It is dense enough that it doesn't blow away. It attached in a couple weeks also. The fragged piece (a finger like projection) has since broken off (by accident
) but a half dollar size patch of polyp covered coral remains on the rock. Pretty cool.