With repeated bank withdrawals of initial overall fund, if the margins are good enough, then eventually busting out doesn't matter.
So I would only have to recover my initial say £100 one time over the period to be level. If I figured I could make and withdraw £100 a few times before a bust, and do that more times than I don't do it, then surely my staking plan works.
I am not using one, but I can see how it can work.
Obviously, the points made in previous posts above hold true in the vast majority of occasions.