This is going to sound crazy... when the owners are in the room, and the dogs are out of control, TALK TO THE DOGS! Just grab one by the jowls (gently, of course), look them in the face (but not threateningly), and tell the dog that you love him but don't like getting slobbered so he has to go lie down somewhere.
If the "dog" doesn't get the message (i.e., the owners), grab the next dog and repeat the message, just little louder. If all esle fails, shepard one of the dogs into another room and close the door with a "Love you! Now go lie down."
Cheeky yes, but you're on the hairy edge (pun intended) of losing or altering the friendship, any ways. :-)