Not really gigging, but we used to catch frogs for bait via the pole & line method mentioned, but with a particular "bait". We would take about 6 feet of 4 lb or other very light monofilament tied to a pole. At the business end we'd put about a size 8 or 10 straight-shank fishhook baited with a piece of red cellophane strip from a cigarette pack. The cellophane strip was about an inch long. Don't want to make it too big lest the frog miss the hook when it goes for the bait.

To catch the frog we'd just dangle the piece of cellophane a couple inches in front of the frog's nose and either jig it lightly or wave it around gently. The frog would eventually go for the baited hook, even jumping to get to it if needed.

I understand that you can also use a small (3/4" - 1" long) triangular piece of red flannel as the bait instead of the cellophane strip. Not sure what it is about the red color to the frog's mind, but they sure went for it. We didn't even have to be careful about hiding or covering the hook. We'd just hook the cellophane strip onto the bend of the hook, wave it around a bit in front of Ol' Froggy's nose a bit, and haul him in when he jumped & grabbed the bait.