Does the hair spry help it hold? I can't see it having much sticky property to it.

It depends on the surfaces - but that is a common trick for getting bike grips (MTB & motorcycle) on w/o an air compressor, and helping them stick.  When wet, it acts like a lube, and after it dries, it's a light adhesive.  Usually both surfaces need to be very clean.  Generally, it is better to try them dry first, and if any slippage occurs, then clean the grips and bars and apply a tiny burst of hairspray.  If that fails, motocross grip glue works wonders ;)