Bollinger Bands may be used in any type of market, except where the liquidity is low. Their greatest utility is probably when used for short term swing trading in highly liquid markets.
Bollinger Bands are a specific type of a general indicator class that seeks to profit from the way trends and trading ranges oscillate above and below a moving average or price level respectively. The particular strength of Bollinger Bands is the way they expand and contract reflecting the relative volatility of the price data. A general observation is that strong directional moves tend to follow contraction of the bands and so of the volatility. A similar observation has long been used in the triple moving average system with the concept of clustering. Bollinger Bands also seem to allow some guide as to how far a move will go in that it seems to go from one band to the opposite band. They are not a magic indicator, but a useful addition to the trader's toolbox. They require some practice. Like all technical analysis tools, if they are not comfortable for you, look for another tool that does the same job.