Goodness, I have never heard that one before. Here is a link with some good information on babies spitting up:
Here is a quote from that link:
"Spitting up, sometimes called physiological or uncomplicated reflux, is common in babies and is usually (but not always) normal. Most young babies spit up sometimes, since their digestive systems are immature, making it easier for the stomach contents to flow back up into the esophagus (the tube connecting mouth to stomach).
Babies often spit up when they get too much milk too fast. This may happen when baby feeds very quickly or aggressively, or when mom’s breasts are overfull. The amount of spitup typically appears to be much more than it really is. If baby is very distractible (pulling off the breast to look around) or fussy at the breast, he may swallow air and spit up more often. Some babies spit up more when they are teething, starting to crawl, or starting solid foods.
A few statistics (for all babies, not just breastfed babies):
Spitting up usually occurs right after baby eats, but it may also occur 1-2 hours after a feeding.
Half of all 0-3 month old babies spit up at least once per day.
Spitting up usually peaks at 2-4 months.
Many babies outgrow spitting up by 7-8 months.
Most babies have stopped spitting up by 12 months.
If your baby is a ‘Happy Spitter’ --gaining weight well, spitting up without discomfort and content most of the time -- spitting up is a laundry & social problem rather than a medical issue."
I think if he is spitting up after every nursing maybe try feeding on just one side each time would be something good to try. If you are really concerned, especially if he's showing signs of distress, you might try contacting a La Leche League leader or lactation consultant (IBCLC) for one-on-one support. They can guide you much better than anyone can over the computer.
Is there a La Leche League Group in your area? The leaders will help you for free. Here is the link to find one:
How to Find a La Leche League Leader Near You