I should point out that as most of you are already aware of, this proc lands independently of the mezz, and consequently, can land whether the mezz is successful or not. As it has a 3% chance of landing and a 3% attack penalty per level, maxing at 15% chance of landing for 15% attack penalty, it's definitely a viable debuff.
A useful strategy would be to use a mezz that is capped too low for the targeted mob. Spamming this mezz will eventually cause this debuff to land. For those of us fighting mobs above level 73, the Stasis mezz, which is capped at level 73, will work nicely. Since the recast is instant on Stasis if the mezz fails to land, using this AA on mobs above seventy-three will cause this mezz to instantly reset. With its fast cast time of 1.5 seconds and instant reset, you should be able to have this debuff on the mob in seconds.