꼬 here is a southeastern (Gyeongsang) pronunciation. Most of these lines are 가꼬, the local form of 가지고 'and so / because': 그래가꼬 내가 내렸는데 'so I rolled mine down.' One line has 무꼬, the regional 뭐고 'what is it?' The remaining lines (똥꼬, 꼬르륵, 석꼬) just happen to contain the syllable and are unrelated.