All you'd need is one trusted friend and your own primary account.
Pass over a hold full of expensive goods to your friend from your primary account, sign out and back in with your secondary and they pass it back. Sell, rinse and repeat.
I think someone on the main Distant Worlds thread mentioned giving his son a load of credits that way and Frontier automatically disabled the account because it had been accumulating money too quickly. But used in moderation it could certainly speed up the process.
Can't find the post I'm afraid.