Hate to point it out, but...
on a standard Martingale (doubling each loss) you would not be able to cover the bet on the 6th spin.

with your revised plan - which does not allow you to win back all your losses at once, but I assume you knew that flaw already - you would have 13 spins. And if you only won on that 13th spin you would have spent £91 for a return of £26... Even the FTSE 100 is better value than that.

*note - zeros are not included for simplicity.
**note - gambling is for fools
***note - that hasn't stopped me racking up alot of debt as a result.
( The Teviot Moose major 5th., Wed 13 May 2009, 10:47, Reply)