I think pull-throughs are substantially similar (if not identical) to using a "core-blaster", which is easy to make.
Basically, you go down to your local Home Depot or Lowe's and
pick out a 3/4 inch diameter flange that
is a foot long. Then, a t-joint plus two
more flanges each about 6 inches long.
Finally, get a footer, to make the
base of the core blaster.
Attach the t-joint and the
footer to opposite ends of the longer
flange. Then, screw the two smaller
flanges into the two ends of the t-joint
for the handle. Then, just slide 3/4 inch weights down the large flange. (Thanks to Dan John and his website for the details).
Works like a charm.