I've got a 20 year old Lowden that Ive been using FF on for most of that time and the fretboard ebony is in perfect shape. I used to use clarinet bore oil and sometimes lemon oil on fretboards but they seem to collect grunge more easily and required more frequent cleanings whereas applying FF is about all the maintainence I perform nowadays and it works quite well on my newer instruments as well.
For strings I generally buy Newtones 6 sets at a time for about $8.00 per set w/shipping and they last so long it works out to be a bargain.
Interesting stuff, John. vl