The need for lube is more extreme outside
I've stuck cases because of insufficient lube outside the case, but never because of insufficient lube inside the case neck.
Thirty years ago, my Metallurgy professors told me that at a microscopic level, without the lube friction causes enough heat in very small areas that the cases in very small areas form a metallurgical bond with the die. The intermetallic areas are not deep, nor are they large, so they are weak, but without enough lube it may be enough to stick a case.
If you are going to lube inside the neck too, make it a lube you can remove, and prefer something that does not kill primers. I don't bother lubing inside necks anymore. I have used some wax-based, and also mica, applied with a brush or mop. Some commercial manufacturers make an assembly that will hold the brush/mop and lube, one of them being the Forster I have.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=301357&t=11082005
I don't think the mica or wax lubes did much good inside the neck, but some while ago I saw an article on the SurplusRifles board about using electricians wire-pulling lube inside the case neck, and it reducing case elongation after resizing:
http://www.surplusrifle.com/shooting/homestretch2/index.asp
Normal size dies first make the neck way smaller than necessary, then expand it to the appropriate diameter. I have moved in the direction of using Redding adjustable dies that size the outside of the neck such that the inside of the neck is the appropriate diameter:
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=326633&t=11082005
CDD