Your best guide on how to clean a fabric is the care label, which by law must be sewn into all articles of clothing. If the label says a garment must be dry-cleaned, follow that advice, or you will have no recourse with the manufacturer or retailer should something go wrong. If the label permits hand washing, you have to decide how to wash it. But I guess, before you buy the garment, you must read the label if it is dry-cleaned or not.
Honestly, I have a sweater that I forgot to read the washing instruction. I didn’t know that it should be dry-cleaned and not for regular washing. To my dismay, the sweater shrunk when I took out from the washing machine. I almost cried for it was new but I couldn’t blame anybody for I know it was my entire fault. I didn’t read the label or washing instruction when I bought it from the local store nearby. Now, I have learned my lesson. I must read the label of the garment before buying, or washing it.
I think you already know how to wash clothes using a washing machine, don't you? If not, then you can read the manual of your washing machine, otherwise if it's commercial one, you have to read the back of the cover of it --- you can read it by the way before you place your clothes or soap inside the washing machine. Happy washing then! :)