A handle-sheath may be molded for of a flexible material and may be shaped and dimensioned so as to be stretched over a conventional handle, thereby permitting the sheath to be conveniently removed and replaced. An internal flushing mechanism is preferably provided for sanitizing the interior of the sheath without requiring the sheath to be removed from the handle. The handle sheath may be molded from a tear-resistant, soft touch, elastic polymer such as thermoplastic elastomer (otherwise known as "TPE"). The interior may be provided with inwardly facing support studs and/or channel walls which define a plurality of individual-contact areas between the sheath and the handle, each of which providing a respective localized intimate contact area for frictionally securing the sheath to the handle, and at the same time defining channels which facilitate the maintenance of a sanitary condition between the handle sheath and the underlying structure, as will be described in more detail hereinafter. The sheath is preferably provided with one or more attachment points to which may be attached a loop or strap adapted to be gripped by the user as the sheath is being installed or removed onto the knife handle, and/or which may secure the user's hand to the knife during use.