Transmissions normally began to leak as the seals or gaskets get old and
harden or deteriorate. There are some products that will soften or swell up
the old seals which will temporarily decreases the leaking. The problem is
that they soon begin leaking again, only worse than before.   In your case,
there should be no old seals or gaskets, so the leak is more likely a
mechanical problem rather than one of deterioration.  I would suggest
parking the car on a clean slab or over some card board. Observe where the
fluid drips onto the surface and then take a close look in the area above
the drip. You might just find that you only need to tighten the pan gasket
or maybe replace a transmission cooler line hose clamp. There are a number
of places the leak could come from, but since you recently had it overhauled
it will probably just be something loose rather than something that needs
replacing. If you are adding that much transmission fluid and there are no
puddles of fluid on the ground where you park, then there are some other
things to check that could be causing the fluid to be consumed. Post back if
that is the case. BTW, make sure you are checking the fluid level correctly
and not overfilling it.

good luck,

STOP! Don't put anything in that trans until you have some
idea of what your are trying to do.  First, you haven't
bothered to mention what make, year model or other pertinent
info that may be needed to get some idea of what your
problem may be.  There are several causes of transmission
fluid loss that may or may not be related to something that
an additive may be helpful with.  These additives are
usually effective for the short term and may result in other
transmission problems if they work at all.  You may have
another problem with which an additive may not be effective
at all while risking other problems.  If nothing else, call
the person who built the trans.  Phone calls are still
cheaper than a screwed trans.  They may have knowledge of
something easy since they built it in the first place.  When
I build a trans or any other repair, I consider it an insult
for the owner to call someone else before they ever bother
to ask me about a problem.  I think most others who take a
bit of pride in their work feel the same way.  If that
doesn't get you anywhere, please post back with more info so
that someone here may be able to offer some relative advice.

Regards
Lugnut

You didn't say how much you have to add, but having to do it two to
three times a week is a lot.  Certainly far beyond what you could
expect a stop-leak product to accomplish even if this were the sort of
problem within its realm (slightly dried and shrunken gaskets, etc.)

Also, something going wrong that badly could get worse with little
warning.

You need mechanical repair, which as others have noted could be
something minor and external and well within the abilities of a general
do-it-yourselfer type.    Give it a chance to be easy.

The first step is to clean things off with old rags or paper towels and
figure out where the leak is.  Just be sure to take safety precautions
for  working under a car (safety glasses, proper lifting and
supporting, etc.)    Wear rubber gloves and old clothes too, since a
large-scale transmission fluid leak tends to carpet-bomb the underside
of a car with dirt-attracting petrochemical yuck.

Cheers,
--Joe