You should be doing that but not with all your money that is the trick, there is a huge chance you won't lose twice in a row so at the end of the deal you could just say "10x when I lose" and you will make a profit, sure you can lose twice in a row eventually but until then you won't be losing any money and you would be also making a good wagered amount.
Say your bankroll is 1 btc (which means you are a whale in my eye, this is for people with less money, however lets say 1 btc for sake of example), you can bet 0.01 on 1.01 and if you ever lose you can bet 0.9+ and win it back, then you could continue with 0.01 like nothing happened, this can continue for a long long time. It is certainly a risky move and you may end up with a lot of loss but if it works you could make a huge profit.
Conceptually, it is a very good strategy, but in fact, when betting, it is not what we expect, certainly between bets, we will feel more than 2x loss, either at the end or the beginning. I myself have used the strategy you mean, but ended up losing. I have set a winning limit and a loss limit but between each bet there is always a loss of more than 2x, so more funds are needed to carry out this strategy or bet a small amount.
And I try to bet a small amount which means my funds are sufficient to anticipate 5x losses but finally I still get 5x more losses between bets.
