Step #3: Clean Sink and Strainer
Use a putty knife or abrasive pad to remove any hardened plumber’s putty from around the strainer opening inside the sink. Follow this with a damp sponge and dishwashing liquid to remove any remaining putty reside or grime around the strainer opening in the sink.
If you’re reusing the existing strainer, clean the underside of it thoroughly as well. On new strainers, wipe off the underside of the strainer with a cloth or paper towel.