Fill a bucket with 1 gallon of tepid water. Stir in 1 tsp. mild laundry detergent.
Submerge the crochet piece in the soapy water. Hold the crochet piece from underneath while keeping it submerged in the water. This helps support the weight of the wet piece and prevents it from being stretched during the cleaning process. Gently squeeze the item to work the soap into the yarn.
Lift the crochet piece out of the soapy water. Squeeze it lightly to get rid of some of the excess moisture. Fill the bucket with cool water and place the crochet item back into the bucket. Gently squeeze and move the crochet item around in the water to rinse out the soap. Repeat this step with fresh buckets of water until all the soap has been removed.
Lay the item flat on a large, clean towel. Roll the towel up and press against it with your hands to absorb water out of the crochet item. Repeat this with dry towels until you've removed as much moisture as possible from the item.
Place the item on a sweater drying rack that allows air to circulate under and over the crochet piece as it dries. Manipulate the crochet piece so it's lying flat, in the shape in which you want it to dry. Secure the item in place with rust-proof pins, then allow it to air dry completely.
Fold and store the crochet piece in a plastic storage bin.