It may make an excellent swing indicator as it gives quite a bit of room for trends to develop. It is slower than other trailing line indicators like the Supertrend indicator. The indicator is simply the outer Bollinger bands but the differences between this and normal bollinger band are:-
1) Only one of the bands is drawn at any give time. In downtrends it is the the one above and in uptrends it is the one above.
2) Once the line as made a new low (in a downtrend) and a new high (in an uptrend) it does not print higher or lower respectively until the trend is broken. Thus a normal bolly band may rise at points in a downtrend but this indicator will just keep plotting a sideways line until the bollinger band makes a new low.
This metatrader indicator can be used on 4hr charts although the one above is a 1 Day chart and could help in your swing trading