maybe try a hemp or bamboo prefold in them instead. I use a different brand of cloth, but a friend uses gdiapers and she put in prefolds instead of the gdiaper inserts. She said it worked better and was cheaper.
I would just use a prefold in the gDiaper pants. I did that a lot. I kept the disposable inserts on hand (just the ones that came with the diapers) for when we were going out, but when I got the gDiapers, they hadn't started making cloth inserts for them yet, so I just used prefolds.