The use of collective as a "brake" depends on several factors, such as type of surface, forward speed, slope etc. etc.. In some helicopters the run-on speed is so high as a norm that you must lower the collective to stop (e.g. the Scout). Just be careful with how quickly you apply the collective braking force, only apply as much is as necessary to safely bring you to a stop without digging a ditch with the nose of the aircraft!!