Vacuum the carpet thoroughly
Sprinkle baking soda evenly over the carpet
Let it sit for 15 to 30 minutes
For odors or deeper cleaning, leave it on for several hours or overnight
Gently brush the baking soda into the carpet fibers if needed
Vacuum the carpet slowly and thoroughly to remove the baking soda
Repeat on stubborn spots if necessary
Test a small hidden area first if the carpet is delicate or colored