I am sure that everyone has its own ways on trying to manage this problem with our engine. I have owned my X5 for 9 years now and replaced the CCV once. I use my X5 to commute to work and it is only 15 minutes driving distance, not enough to warm up the engine and I spend months without going for a long drive. I have kept my engine/CCV cleaned using my simple and effective method in this link:
http://www.xoutpost.com/bmw-sav-foru...tml#post812284
As stated in the last comment, The only thing I do now every month(winter) is disconnect the hose, picture #8 from the cover and suck in most of the mayo from the cover and the CCV hoses.