Do the Frame saver!!!, especially if you live in a humid or salt air climate. It's a very, very good Idea. If I ever "get off the pot" I'm going to coat ALL of my frames!!!! I'm not sure I'm going to use the same suff, there's lots of ways to do it.
Don't worry about getting it in your Bottom Bracket Shell and "mixing with the grease", the stuff dries pretty hard and almost all BBs have plastic sleeves to keep junk out, ( if yours doesn't have a sleeve you can get one), and the new ones are "sealed". Actually, having a layer of "saver" in you BB shell is important.

"Steel is Real"

Ride Ferrous
Pat