You can't use Apricorns to create a GS Ball in "Pokémon Soul Silver" nor "Pokémon Heart Gold." You can use Apricorns to create Fast Balls, Friend Balls, Heavy Balls, Level Balls, Love Balls, Lure Balls, and Moon Balls.
Originally, the GS Ball was obtainable as an event item in the Japanese version of "Pokémon Crystal." When the player had a GS Ball, she could go to the Ilex Forest and catch Celebi. This is, so far, the only opportunity to catch Celebi in any Pokémon game. The GS Ball has never been legitimately available to players outside of Japan.