As you use your Sebenza, the mating surfaces of the pivot "break in" like bearing surfaces in a car engine. At that point in time, the pivot gets
silky smooth. Nice feel!

After break in, I tend to lube my Sebenza when it loses this smoothness.* For my EDCs, the clean/lube interval is not so much dependent on time, but rather
how I've been using. If I've cleaned a bunch of fish, for instance, my Sebenza's gone through several cycles of gunking up and under-water shaking to un-gunk (number of cycles go up with the trip's increasing success rate . . .

). Within a week of fishing, I'll have cleaned/lubed my Sebenza a 2-4 times. Conversely, I've not done any dirty work with my large Sebenza EDC since mid-summer. I followed up that work with a clean/lube job, and it's as smooth silk today as then.
As for my cleaning method, it's the one in TedV's most excellent sticky note here:
http://www.bladeforums.com/forums/showthread.php?t=260685&page=2
The only difference for me is that after cleaning the parts, instead of oil, I use a small spot of CRK flourinated grease. BTW, this is all it takes; adding more just makes for excess lube that has to be worked out of the tight tolerance pivot (and the pivot is a bit stiff when over-lubed during this process). Go easy on the flourinated grease, and a syringe will last a lifetime of lubing.
* BTW, I wasn't always like this. Used to go a couple years w/o cleaning my EDCs. No problems with very infrequent cleanings. I just seem to have slowed down to enjoy things a bit more in my old age . . .