I just use wax paper, or a piece of plastic between the piece I'm gluing and anything that I don't want it glued to. But, I'll detail how I use CA to glue binding. You won't have to worry about anything sticking to your fingers or tools.
Prep:
It's very important to THIN CA glue. You may have to go to a woodworking store, like Woodcraft, to find the right CA glue. Don't use the gel type. You want the glue to run down into the seam. If worse comes to worse, and you can't find CA glue marked as thin for woodworking, you can use the stuff you find at places like home depot, but make sure it's really runny.
First, it's important to use a finish in the routed channel which the binding will be glued, around the spruce top. I use shellac. Shellac is safe to use under all types of finish. If you don't use a finish, the CA glue will discolor the top, because it will soak into the end grain. Also, if you plan to stain or dye your sides and back, I would go ahead and do it before using ca glue. The ca glue will soak into the pores and will prevent the wood from being stained or dyed.
CA glue will adhere to almost all finishes. If there is any question, first test by applying your finish to a scrap piece of wood, then use ca glue, to glue a little scrap piece of your binding.
Procedure (3 variations):
Tape the binding into place with masking tape, leaving a 1" gap between each piece of tape. If usng thin ca glue from a woodworking store, use a plastic pipette, which has been stretched to make a long neck with a small opening (see video). Suck up the THIN CA glue into the pipette. Squeeze a line of ca glue along the top seam of the binding, in the exposed binding, between the pieces of tape. It will wick it's way down into the binding and purfling. Don't worry about the seam under the pieces of tape right now.
It doesn't take much, and you'll be putting more on when you take the tape off. What you're doing now, will hold everything in place, until the final gluing. So, what you will have, is basically 1" of glued binding, then 1" of unglued binding. Don't worry too much if a little gets on the tape, because the tape will scrape off when you scrape the binding down.
When the ca glue is dry, you can do one of a couple of things. You can remove all of the tape; the binding should be adhering well right now. After removing all of the tape, reapply the thin CA glue along the entire binding and purfling. Keep a paper towel handy, in case you get a bit glue happy and it runs down the side, or if it's really heavy. Just wipe it off quickly with the paper towel.
Or, you can remove the tape and squeeze glue on each area that was taped, and tape over the areas already glued and dry.
I usually remove all of the tape, then apply a good line of glue around the entire seam, including the purfling. The glue will go down into the purfling and binding, gluing everything. When it's dry, scrap it down.
The third way is to tape your binding into place, like you would if it was already glued, pretty much covering all of the binding. Then, remove every other piece, and apply the glue, then retape it. Again, you may have to scrape off some tape if it adheres to the glue, but it scrapes off readily.
Here's how to stretch a pipette. If you're using small bottles of thin ca glue from a big box store, just use the tip on the bottle. But, a larger bottle of CA glue should be applied using a pipette. You can find these at woodworking stores, Amazon, or other online places. You may find them in a hobby shop.
https://youtu.be/ZQvW_nULD18
If you have any questions, or if you need photos, just let me know.