No it is assur, for through trying to come up with shtus you will inevitably run through actual Torah in your mind. This is so even if you wanted to, for whatever reason, read kefira in the bathroom which of course technically has no kedusha

No it is assur, for through trying to come up with shtus you will inevitably run through actual Torah in your mind. This is so even if you wanted to read heretical books in the bathroom which of course has no kedusha, yet since you will inevitably think of torah it is prohibited.