We have methods were are provable and verifiable. Why risk everything by coming up with your own ad hoc scheme?
would you consider using a trezor or ledger or some hardware device that you can't really visibly verify what is going on you have to trust that it is generating random numbers? i have a hard time with that. every time i ever thought about using some hardware wallet to do that, i thought maybe i should do one or two just to get it "warmed up" so that's how little i trust an electronic device.