Yeah .... if you are wanting to use the effect on the way in, it would go in between the preamp and the input of the 44. Also some preamps offer insert points that can be used for routing in effects.
Another method would be to record the instrument/vocal dry (with no effects) then assign that track to one of the 44's outputs, which would then go thru the external effect and back in to one of the 44's inputs and recorded as a new track. Although, this method creates additional D/A and A/D conversion and can run the risk of track offset due to latency (unless your program automatically offsets for recording latency).
If it's an effect you know you want and are content with it's sound .... no reason to not just use it on the way in. The only drawback is that it's printed that way and there's no turning back without a retake.