I clean and grease mine about every 6k miles. Could probably go longer but not a major hassle. Have done one HT2 BB three times now and no problems with damaging the seals. Just use a thin blade of some sort to pry the seals off, it's as easy as your video shows, no surgeons skills needed. Then do as richart in post #2 suggests. If everyone knew how easy it was to do this I think Shimano's sales of replacement BB's would be reduced by 90%.