completed cross stitch

Ideally, wash the thread before you start. If you have already completed the project and need to clean the thread/fabric, you have a couple of options.
1) Take it to a cleaner that is experienced in cleaning needlework.
2) Wash it CAREFULLY in the sink in cold water. I’ve used woolite, but I’m told Cascade dishwasher soap is good as well (I’ve used that to clean antique doll clothes). If you choose this way, do not scrub the stiched area and do not wring out the cloth. Once you have washed the project, press it between layers of towels to remove the excess moisture. If you need to, you can iron it after, again with a layer of towel between the iron and your stitching.