I've done a lot of relic-ing and neck work on guitars over the past year. I haven't tried with a CV yet. I have a CVC and have been toying with the idea of getting the neck to a satin type finish.
Here's what I know...
Fender uses a really thick and gooey poly finish that bonds with the wood on their MIM guitars, and I am assuming that the poly is similar in the CV guitars. The coat of poly is pretty thick and if you want to get through it, you will need to do a substantial amount of work to sand it correctly and not damage the wood.
Here's what I would do...
1. Remove the neck, take the tuners off.
2. I would not mess with any part of the neck that touches the body of the guitar, because you don't want to change the fit of the neck with the guitar body. I would make very light markings that I would not sand past on the base of the neck.
3. On the headstock, if you want to make sure that the Squier logo stays intact, I would only use some steel wool. (and then follow the finishing techniques for the rest of the neck.)
4. On the back of the neck, I would start with a coarser grain sand paper and then work my way to a fine grain sand paper and eventually to some fine steel wool.
5. I would use the coarse (100-110 grain) paper and thoroughly sand down the entire back of the neck. Alternate going long straight strokes to circular strokes. (Always end with long strokes though) When you do this, the poly will come off like a powder. Don't worry, it's not sawdust, it is just the poly. Do this in a well ventilated area, as you won't want to inhale the poly dust. Once the whole back of the neck looks super dusty, use a grease cutting dish soap to clean the dust off. I like to use clorox wipes that you would use in the kitchen. (If you don't clean as much dust as you can off, when you sand, you are just smearing poly by reheating it and digging it deeper into the wood.) Once you break through the poly to the wood, you will know because the dust will be dry and brown rather than white. I'd prefer to not break through to the wood until you are using a finer grain sand paper.
6. After doing this with the 100 grain, move to a finer paper and repeat. If you break into the wood, stay away from the area where you broke through until you get through to the wood at the same depth on the rest of the neck.
7. As far as the headstock is concerned, you have to decide whether you want to strip the logo off or not. If you don't, just rough it up smoothly with a very fine grain paper and use the same clorox wipes to clean off the poly dust. You will want to treat the headstock with the same oil that you use to treat the rest of the neck.
8. An important thing to note is that on the headstock or even on the neck, you might still see some scuffed up poly remaining there. As long as you have scrubbed it off as much as you can with a clorox wipe, the oil will take care of the powdery look. Don't feel like it has to look perfect before you treat it with the oil.
9. I like either Tung oil or Linseed oil to finish. I think that most people are partial to Tung oil. I would liberally apply it to all areas that you have sanded, and let it sit for a couple of hours. when it is done sitting, it should feel a little sticky still. Take your finest steel wool (i use #0000) to go over the oil. This should take the sticky off. There have been several times where I applied the oil 2-3 times to get it looking and feeling right. If you don't like how it looks, You can always sand a little more and then apply oil again.
I did this to a MIM Strat neck not long ago, and it feels absolutely perfect to me. I did this to a Squier 51 neck as well and it just turned out amazing as well.
I hope that helps. I have a CVC that I am toying with doing the neck on, but the whole guitar is so dang beautiful that I don't know if I can touch it with sand paper for a while. We'll have to see.
