Stormsure or aquaseal works great. Ideally you get a round plastic plumbing coupler that fits over the valve and weight on top. 24 hrs later, done. Those stick on valves we found just peel off unless they are the ones using tear aid sticky back. .
As said, use the storm sure and get a weight on it overnight. A few rolls of electrical tape stacked up with some weight sitting on top fits perfect as well.