I need to make a spiral groove in a couple of columns. I only have to
do it in two columns and I may not do another for a LONG time, so a
complex jig that will take room and time to build is not an attractive
approach.

An alternative way is to put a grid pattern on the column and join
points along the grid to make a spiral groove manually using gouges
and chisels. That is a possibility, but I am afraid of how tedious
this would be and my ability to make a clean, attractive groove using
this method.

I wonder if someone has a BLEND of a simple jig and a manual layout
that might use something like a follower groove as a path for a
follower arm attached to a router. Has anyone come up with something
like this?

If not, and the manual way is the way to go, is there someplace on the
web that goes through the steps for doing this that will help me be
successful?