This is a controversial issue and many people have different opinions.
Some people feel that coffee grounds are safe for your disposal, while others think they may clog the pipes. The real key issue is what type of garbage disposal you have and what kind of plumbing system is installed.
Check with the manufacturer of your garbage disposal for a recommendation.
Some manufacturers will say “yes” others, “no”.
In fact, some manufacturers may encourage the process stating that it will help keep your disposal smelling fresh. The issue is also whether or not your septic tank can handle the coffee grounds.
Many people recommend using coffee grounds to help freshen the garbage disposal. Other recommendations include grinding up lemon and orange peels.
However, you may find that the best way to keep your garbage disposal smelling fresh is to fill the sink at least 2/3rds full with soapy warm water, pull the plug and turn on the garbage disposal. This creates a high-powered suction effect that will keep the disposal clean.
If you feel strongly about putting coffee grounds in your disposal, check with the manufacturer’s recommendations first.