<pedantic>But what is an indicator?
Sure oscillators and MAs are indicators. What about trend-lines, Fib levels, pivots, donchian channels etc. Are these also not derivative constructs of price, and therefore indicators?
Nizar mentioned the Turtles, who used a Donchian channel system. Donchian channels are still indicators in my book, as they derive from price history. They are drawn on the chart, referencing the previous hi/lo point in the lookback parameter, much the same as a moving average.
Even trend lines do this.
True indicator-less trading is just price bars... and nuttin' else.</pedantic>
Interesting perspective, Wayne.