I’m sure you have at least one countertop that rests against a stove or other appliance that has a slight gab that collects crumbs and grease. It’s very hard to clean unless you pull the stove out and who wants to do that? An easier cleaning method would be to wrap a butter knife with a microfiber cloth. Spray some multi-purpose cleaner into the crevice and now run the knife in the gap. The knife should be narrow enough to grab any grease and crumbs down there. The cleaner will help disinfect the area too.