I think the one you are referring to is a "Stop and Reverse" kind of martingale wherein once a position is Stopped Out, it will take the opposite trade at a higher lot size (not necessarily double - there is math to it). Rinse Repeat until it exited at a profit. This kind of martingale has one achiles heel : Consolidation wherein price would move up/down thereby hitting SL many times and building up the lot size... I've tried it and didnt like it... I tried to prevent it from trading during "dull hours" with little help only. Some have success...
Ignored
I would be very interested to find out more about the Grid style martingale system, if there is still motivation from your side to develop it further...