USB Debugging mode for flashing?

[iceburnmarko]

I read guides that say u need USB debugging mode for flash (or at least I guess they recommend it) which is what I follow in the past to update the firmwares on samsung I9000 / i9100 phones. But got two phones. First phone got too many pattern attempt, with google account + password. But account does not work, tried hard reset and still got account login part.

Tried to use the dongle to remove google account but since usb debugging mode is disabled on it, it can not do it. Try the bypass but does not work.

So I was thinking of flashing it but than I just remember about those guides to say USB debugging mode, turn it on. So I am asking could I "reflash" this phone to get it back to factory setting if usb debugging mode is not on and at the moment look likely will not be able to turn it on. (i9000)

Whilst got I9100 which has got a password, tried recovery, but that ask for password as well. So wondering if can flash that one as well. (will look since that might have debugging mode on hence can use dongle.