Cover detergent pooling in the bottom of the dryer interior with cat litter to absorb the detergent. Allow the cat litter to absorb the detergent for 10 minutes.
Wipe the cat litter out of the dryer with paper towels and discard in a trash bag. Repeat the addition and removal of cat litter if needed to remove as much of the spilled detergent as possible.
Fill a bucket with 1 quart of warm water. Add 2 cups of white vinegar.
Soak a clean sponge in the diluted vinegar solution. Wring out excess moisture.
Wipe out the interior of the dryer with the vinegar-dampened sponge to remove any remaining detergent residue.
Rinse the sponge with warm water as the detergent residue is removed. Add more vinegar to the sponge, wring it out and continue to wipe the surface until there's no more detergent left.
Dry the inside of your dryer with a clean cloth.