I've been bottling every batch for 19 years. A little fresh yeast is all that needed. Don't even need a whole pack. I wouldn't add some to every bottle, just a little to the whole batch. A day or two before bottling, I would add like 1/4 pack of yeast per 5 gallons directly to the fermenter, no rehydration necessary. Then monitor to ensure fermentation doesn't take off again -- if it does, you'll want to leave it alone until inactive again. If all seems calm, then go ahead and bottle. This will be enough yeast to carbonate your bottles for you.