What gear were you in when you tried? Obviously the higher the gear, the easier it is for the wheel to drive the engine.
I don't see why an increase in cam chain tension at the back should encourage the tensioner to tighten, but if people say it works then I guess it does.
>edit<
Ooops, too early in the morning for logical thought... rotation's the wrong way, but yes, the tension is going to be at the front run of the chain.