You know how noisy the Bollinger Band (BB) stochastic can be. It is for the same reason the standard Fast %K stochastic is noisy: raw price is very jittery.

In this experiment, we first smoothed raw price with JMA, calculated the Bollinger Band around a JMA center line, and then evaluated the fast-K stochastic. As shown in the chart, almost all jitter was removed with no apparent lag in the final signal.