Chazzy
The vacuum line to the ECU comes directly from the actual airbox, and due to the large volume, the depression felt in this line is possibly not going to be enough to operate the Oiler.
It might well be worth trying as long as you do nothing you can't reverse if it doesn't work. However it would be a toss up between the likelyhood of it working or not and wasting time, against doing it as per the instructions in the first place.
It really isn't that much of a deal to remove tank and airbox, my opinion is use the convoluted tubes on throttle bodies as per instructions.
This page shows what your looking for,
http://www.scottoiler.com/support_guide1.asp
