Apparatus for sealing a vascular wall penetration disposed at the end of the tissue tract comprises a shaft, an optional occlusion element, a hydratable hemostatic implant, and a protective sleeve. The apparatus is deployed through the tissue tract with the occlusion element optionally occluding the vascular wall penetration and inhibiting backbleeding therethrough. The hydratable hemostatic implant, which will typically be a biodegradable polymer such as collagen carrying an anti-proliferative agent or coagulation promoter, will then be deployed from the sealing apparatus by retracting the protective sleeve and left in place to enhance closure of the vascular wall penetration with minimum scarring. The hydratable implant will be protected from premature hydration and swelling by a soluble plug covering the implant's distal end prior to sleeve retraction.