Case lube, like RCBS or even Hornady one shot will work just fine too. Both are made as to not cause any issues with the powder. Not sure if you've got a tumbler, but I always tumble after resizing anyway to make sure that they're squeaky clean before I reload them. I just neck sized some 30/06 cases an hour ago and all I did (and ever do) was use a nylon bore brush on an RCBS handle, rub it across the lube pad then run it into the case neck. I'll generally do 4-5 at a time then relube the brush. Although I haven't found it all that necessary, I still FEEL like it is, so I'll lube the outside of the neck on every 2nd or 3rd round or so just to make sure that the case neck glides into the upper part of the die easily.