Pour a 50/50 mixture of white vinegar and warm water down the drain. Vinegar kills the mold and mildew that creates the slimy sludge. Let it sit for 10 minutes, then flush with one more round of hot water.
Don’t panic if the water disappears. That is a good sign. It means the drain isn't fully blocked yet; it’s just slow. If the water sits there like a sink clog, you’re fully plugged. clogged refrigerator drain
The Silent Puddle: How to Fix a Clogged Refrigerator Drain in 20 Minutes Pour a 50/50 mixture of white vinegar and