Diesel purge through near empty-tank?

[Zacharias]

I need to do a spring Lubro-Moly Diesel Purge treatment on my w123 300d.

In the past I have done the routine of using a container, running the supply and return lines into it and running the car solely on purge (I usually do two cans of purge at a shot). However I have never driven the car that way, just run it on high idle, stationary.

Ok so a stupid question: why not just wait until the tank is way down then throw in the two cans of purge and actually drive it on the purge?

Too much danger of stirring up crud in the tank?

Or do other folks do this lazy form of purge....