These methods are not meant for modern fabric. Fabrics deteriorate with age and can become extremely fragile. Old, embedded stains in antique fabric will not respond to cleaning as when the stain was fresh and the fabric new. Always call your costume or textile museum for advice before you attempt to clean any antique textile. As but one example:

"Oxalic acid [obtained from rhubarb] can remove rust stains from cotton or linen, but it can dissolve nylon altogether!" (Walkey and Foster, p.178)