I just installed a new set of cranks and a BB (both Ultegra) and now I find myself having to retighten the crank bolts after every other ride (even if I tighten them down really firmly)

Could this be a result of too much grease on the threads?--I was really worried about binding.

I was wondering if blue locktite might be a solution? However, Locktite requires a complete DEgreasing of the contact areas and I'm worried that the thread area is so great that it might make removing the cranks difficult/impossible.

Thanks.