I don't do 10-gallon batches, but I use a Koelsch/California Ale yeast blend for my Apfelwein fermentations. I don't have the equipment to see how they are behaving, i.e. whether one strain has become dominant, but the results are very enjoyable. I just keep reusing the same yeast cake. I am sure it'll eventually need washing, but thus far I haven't had any problems with autolysis or other yeast breakdown-related off-flavors.
The Fiesty(sic) Goat Brewery est. 2007 & Clusterfuggle Experimental Ales est. 2009
Primary: Saison, Berliner Weisse, sLambic I, sLambic II, IPA, 70/-
Secondary: Orange Blossom Mead, Flanders Red I
Kegged: Fat Man Porter w/ 1469, Fat Man Porter w/ 005, Centennial Falcon w/ Conan, Centennial Falcon w/ Denny's, Barrel-aged Fat Man Porter, Belgian Dark Strong, Dark Mild