I have never heard of egg shells being a problem and I have been doing it
for fifteen years at our house and we have never experienced a problem that
required a plumber. A couple of times the trap got filled with rice however
that my wife put a whole bunch in at once. Even rice is not a problem if she
does it slowly. I always make sure I leave water running for ten or so
seconds after I put garbage in the disposal and if I put in a whole lot I
may leave water running with disposer on for a minute or so. The link below
may be helpful. --- Steve

http://www.insinkerator.com/disposers/dosndonts.shtml

Do's and Don'ts

The In-Sink-Erator Food Waste Disposer is one of America's most reliable
appliances. However, here are a few simple hints that will keep it working
smoothly for many, many years.
a.. Do first turn on a moderate to strong flow of cold water and then turn
on the disposer.
b.. Do continue running cold water for 15 seconds after grinding is
completed to flush the drain line.
c.. Remember the drain line from your sink may run for 30 feet or more
before it exits your home.
d.. Do grind hard materials such as small bones, fruit pits, and ice. A
scouring action is created by the particles inside the grind chamber.
e.. Do use a disposer cleaner, degreaser, or deodorizer as necessary to
relieve objectionable odors caused by build-up. Peelings from citrus fruits
can also be ground to freshen up drain smells.
f.. Don't fill disposer with a lot of vegetable peels all at once.
Instead, turn the water and disposer on first, and then feed the peels in
gradually.
g.. Don't grind extremely fibrous materials like corn husks, artichokes,
etc., to avoid possible drain blockage.
h.. Don't pour grease or fat down your disposer, or any drain. It can
build up in pipes and cause drain blockages. Put grease in a jar or can and
dispose in the trash.
i.. Don't use hot water when grinding food waste. It is OK to drain hot
water into the disposer between grinding periods.
j.. Don't turn off disposer until grinding is completed.
If you plan not to use your sink or disposer for more than a month, slow
down corrosion by flushing the disposer well with fresh water. Fresh water
is less corrosive than soapy water and it will wash away any remaining food
residue.


"Sasha" wrote in message
oups.com...
I have 3/4 HP In-Sink-Erator garbage disposer. A friend of mine told us
that we shouldn't put egg shells and corn seals into the disposer. Why
that? what else (food garbage) we cannot put into it?