I think I got the frogs to spawn pretty quickly on my last run, I always left a male, female and the golden frogs alone while catching the other frogs.
I then went to play chocobo hot and cold for around an hour and half and around this time I then went back to the swamp. The frogs will usually have respawned at this time and then I went to catch some more frogs.
I just kept doing this process of switching back and forth between chocobo hot and cold and the frog catching minigame.
I caught around 40 frogs I think before the end of disc 1 and dug up all the chocographs in the forest too, I think choco had a beak level of 25-30 odd.
Its a great tip to make inroads in the two games longest sidequests imo very early in the game.
