Swallow the pills rapidly after a gulp of water. Do not leave them sitting on your tongue, flush with water and do a power swallow and this will reduce bad taste. I always take cipro/flagyl with food. I really try not to leave pills on my tongue long enough to be tasted, because they are not meant to be tasted.
A good mouthwash after a power swallow with lots of water should take care of any residual aftertaste. So time your meds after meals and before you brush your teeth and take your mouthwash. This is what I have always done. I use a fluoride mouthwash anyway because it strengthens the enamel on your teeth.