Cockroach is Gokiburi in japanese, that's what the G in the first episode title etc. refers to. I wanted to keep that intact, so instead of Cockroach I needed to use a synonym beginning with G. Gogga was just the first thing that came up on Google. I was thinking about adding a TL Note, but Gogga -> Cockroach seemed like an obvious connection to make from the context. Maybe next time when I feel like I should use some weird word again.
EDIT: ⇈ Changing G to C would have removed the indirect joke of Souta wanting to hit the G(-Spot) for Mino on page 3, but it was an option too, you're right.