I had no luck with grits (my Labradors ate them anyway).  Dish detergent
does work, however.  It was suggested on a local (Augusta GA) radio
program and for weeks got glowing testimonials, until the station was
informed dish detergent was not EPA registered for this use and they
should not discuss it on-air.
 
I've used it for years around catfish ponds as follows:
Tools:  bottle dish detergent (I use anything clear, no dyes), bucket or
hose of water,  3+ foot stick.
Method:  Put ring of soap around stick (for protection), poke holes as
deep as possible throughout the mound.  Trickle a tablespoon or two of
soap into each hole.  Add enough water to bubble soap out of the mound
without too much dilution.  Poke and prod with the stick, adding soap
and water as needed, to get the brood and hopefully the queen.  All
insects that contact soap die, so right near a hive you may want to
flush the surface. A repeat may be necessary in a week or two if you
missed queen or brood, but the new hill will start very small.
 
I treat about once a month or so.  The treated spot stays empty for
months, unless you have a ton of rain, but new mounds spring up
occasionally.    For huge areas it may be impractical, unless you can
get some youngsters who enjoy ant killing.  Of course its impractical to
spend big bucks on very toxic stuff that still doesn't work!  If we
could teach the ants to pour formic acid correctly in the hives...
 
I'm a newbee, been sponging up the list avidly,  figure in about 30
years I might know something.   IMHO we need everyone, scientist,
beekeeper, beehaver, etc.  I was raised in the tropics.  When I was a
professional biologist my best sources on the ecology were often
illiterate farmers and fisherman.  Combine hands-on, seat-of the-pants
with good science and an open mind you've got something... at least
until the chemical companies come...
 
Carolyn Ehle, Plum Branch, SC
Wood Widgeon Farm-- Catfish, fishing, camping, deer processing, pork and
sausage, organically grown vegetables, herbs and nutrition counseling,
and especially bees!  All bee types welcome, prepare to have your brains
picked!