There is no right or wrong way to bowl. There are some methods that make it easier to reproduce shots for most people. Just because it is right for most people doesn't mean that it is right for everyone. Consider the success of bowlers like Mark Roth, Carmen Salvino, Marshall Holman, and even Rick Lawrence.
The "right" method of bowling for you is the method that allows you to repeat shots with the highest degree of consistency. Maybe it is no-thumb, maybe not. The proof is in the pudding.
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Kill the back row (or maybe this should read "make your spares, dummy")