Originally Posted by RM-MN
Suck back only occurs while the beer is cooling. Once it has reached the final temperature you can add liquid to the 3 piece airlock so it won't go dry. In my house it takes weeks for enough to evaporate that that would be a problem. The benefit they have over the "S" type for me is that I have multiple 3 piece airlocks on hand and the LHBS is a 30 minute drive away to get an "S" type and they may not have them in stock when I get there.
Fair enough. I had way too many unpleasant surprises using them. Since I switched over completely to S type, I've not had a problem in years. But if they work for you, that's what matters most.