It has become most common to hear the term "pump and dump" in relation to breastfeeding when talking about managing the alcohol content of breastmilk. The theory is that if you drink, you should pump some amount of milk and dump it before allowing the baby to feed. How much milk you are told to pump and dump varies, but it seriously does not matter, as this is a myth.
Alcohol in levels breastmilk matches alcohol levels in the bloodstream. Pumping breastmilk does not lower the amount of alcohol in the bloodstream, so there is no benefit to wasting a bit of milk. Moreover, the alcohol content in milk will reduce at the same rate as the alcohol content of your blood -- it does not accumulate or last longer in the milk -- so waiting is the only and best way to handle this situation.
But... maybe not waiting very long. When you drink a glass of your favorite beverage, you are (hopefully) taking in 2-8% alcohol (5-15 proof), and ending up with a blood alcohol concentration in the range of ~0.015. That's a pretty significant step-down, and the same step-down occurs in the baby's body when they drink the milk. While it is good to be safe -- even paranoid -- about baby's health, there is no scientific evidence of long-term effects on infant development at this level of alcohol exposure.
And if you do wait, about 2 hours for a glass of wine is sufficient to clear the majority of the alcohol from your bloodstream. Depending on your feeding schedule you might want to pump-and-save before drinking, but light social drinking is 1. not likely to be damaging, and 2. not going to require much of a wait before breastfeeding.
Having said that, there is very little research on the effect of higher levels of alcohol intake on breastfeeding infants. Common sense says don't binge drink with baby. If you drink lots, formula feeding is the way to go -- both to avoid alcohol exposure, and so you can hand the task over to a helper if you get too tipsy; dropping babies and rolling over onto babies while sleeping are both significant risk factors that increase greatly when drunk.
Regardless of your level of concern, pump and dump doesn't work to manage alcohol in breastmilk. In general, pump and dump is only something you do to avoid uncomfortable engorgement, and not to 'clear out' toxins of any sort.
Iron Noder