Currently I also am dual boxing Locks. they are 70 right now. What I do is have strobe enabled. If you are using Jamba there is a feature in the that you can write into your macro that will allow you to enable strobefollow. what this will do is when you cast your drain life or soul it will break follow but once the spell is finished it will instantly start following again (providing you are in range). Aslo one other note to make it wouldn't hurt to have another macro set up that will cancel the strobefollow... comes in handy sometimes.

Unfortunatly I am at work and do not have access to my macros or to many game sites... I am sure someone here can throw in the macro for you but if not I will follow up this evening for you with it.