I'm BB and 3 people limp in. I got this hand:
5♥8♥ 5♠ J♥ K♠
If I change 5♠ and K♠ I remove my weak pair and reduce my chances dramatically of getting two pair or trips but I got a weak chance of hitting the flush. Not to mention that if 3 players exchange 1 card, there is also the chance that 55 might be good if all they did was limping on draws, not to mention the fact that if I get the flush without an ace kicker I might be outkicked or run into someone with house (alltho' it's relatively rare, it seems to happen often enough) and I risk to lose more of my chips than I otherwise would have.
Because of this I've come to the conclusion that if I'm BB with 55 and 2 cards away from a flush, I always exchange 3 cards instead of 2 and I often win more than I lose doing it like this. But.. is it the ''right'' thing to do?