Just an FYI, you can make "clean" loops using ribbon cable. [It's that
flat cable with many parallel wire of different colors. I'm sure you've
seen it before.] What you do is put on insulation displacement
connectors that mate on either end and connect them in a manner where
there is a one pin shift between the connectors. The free pin and free
socket are the locations where you connect to the loop.

The problem with running many wires in parallel is there is capacitance
between the wires, so the loop is really a distributed inductor and
capacitor.

It seems to me what you are not getting in a loop of many turns is a
large aperture. That is, does one big loop act the same as many turns
in a smaller loop? My gut feeling is you would get a better null with
one big loop. The null is quite important in many situations.

I've planned on doing single turn versus multiturn comparisons, but
haven't got around to it. I can tell you that bigger sure is better
than small.
This is a loop 4ft on the diagonal:
http://www.lazygranch.com/images/radio/loop1.jpg
This version is 11ft on the diagonal, and is probably at the practical
limits of this style of support:
http://www.lazygranch.com/images/radio/bigassant.jpg