Hacking or Early Playing
Well, in 2001, when the game was in beta, you first received Throw, Squirt, and Drop as your first gag tracks. So you could get all gag tracks. So if you have a time machine you can probably get all seven gag tracks! Other than that, today, you can hack to get it. But I do not recommend hacking as it is against the rules, it ruins the game, and lots of other things.
To get drop...
To get drop, you first need to get past the Toontown Central tasks. Then, in Donald's Dock, they will ask you to choose between Lure or Drop. Choose Drop and that's how you get it! However, I recommend choosing Lure as Lure is the only gag that keeps the cogs from attacking, and Drop has poor hit percentage.