I would simply dispose of the lipos you have and buy new ones. Why risk your house/car/loved ones going up in flames?
Maybe I am a bit extreme, but how does one "be careful while charging"? Have a fire extinguisher at the standby and watch it charge?
Why even fuss with that and still risk injury to yourself and others? Just plain and simple get a new lipo pack that's safe and you know you can run trouble free.
Ta04-TRF, EVO 5