TopJin, the sealer that comes in the yellow tube with the orange cap (and the product is orange), is the best for azalea. It has fungicides and anti-bionics that help prevent azalea die back. After it dries for a day, I cover it with the grey putty.Wood glue applied with a small paint brush here. If I use nothing on azlalea, die back and bark cracking and peeling away an inch below the cut occurs every time.
I've used this on Grimmys advice for 5 yrs and only used 1/4 of the 4 dollar bottle. I think like everything else in bonsai, it depends... The species, stage of development ect...
I do want to try some other options for the learning experience as my trees progress to where it really matters