I flush, clean, and lube most every GEC that I come across but have found with other brands that I typically don't. While cleaning some new ones today, I oiled the joint on my tribal and noticed the same gunk coming from the back spring that most all GEC's have. From the looks and feel of it the tribal was clean and smooth as can be, but I decided to give it a good flush and clean since I was already in the process on others and to my surprise the Case/Bose took the longest to clean out and produced the most black gunk by far. The tribal is even smoother and snappier now which is great, but I was wondering who else cleans and flushes these collaboration knives, do you find that they are fairly grimy? I suppose it is a good practice for all slip joints but a bit of a surprise on this tribal given its "feel" before none the less.