Is there any way to get a 2nd focus sash in heartgold/soulsilver?

Question

Without trading with a friend

Answer 1

Johto: New Bark Town (Mom's Savings)
Shop:
Johto: Battle Frontier 48 BP
Pokéwalker: Winner's Path (10000+ Steps)

http://www.serebii.net/heartgoldsoulsilver/items.shtml

Answer 2

You can either get it from the Battle Frontier for 48 BP, after defeating the Elite 4, or your mom might buy it for you.