I always use cane sugar to prime. There is absolutely nothing wrong with it. However, I do not measure out portions for each bottle. Here's my process:
1. Rack beer from fermenter into bottling bucket.
2. Check total volume of beer to be bottled.
3. Using
TastyBrew's bottle priming calculator. or my own calculations, calculate the appropriate weight of sugar necessary for my volume from (2), the style, and fermentation temp. I have found some of the numbers on TastyBrew's bottle priming calculator to be significantly off for the style, but most of them are correct.
4. Weigh out this amount of sugar, and dump it into a small sauce pan.
5. Add a little bit of water. Usually 1/4 to 1/2 cup, and heat water to a boil. Stir solution to be sure all the sugar dissolves.
6. Turn off flame, let the solution cool while I prep bottles, caps, sanitizing solution, etc.
7. Pour the solution into the bottling bucket, stirring gently. Let rest about 15 minutes while I continue prep, watch TV, etc.
8. Bottle and cap as I normally would.
However, yeast do not ferment table sugar as efficiently as your usual priming sugar
I think you've got that backwards. Corn sugar doesn't ferment as well as cane (you need to add slightly more, proportionally, for the same carbonation), but supposedly it has a "cleaner" fermentation with less fusel alcohol. However, the amount of sugar used for bottle priming is insignificant, and I challenge you to find any BJCP judge who can actually taste the difference between a beer primed with cane sugar vs one primed with corn sugar.