I have a shower head that articulates, it has a ball joint that is sealed by a rubber gasket (3/8" thick) that is concave to match the ball joint's shape. This joint leaks a little, so I tighten it and the joint won't articulate.<br /><br />Question is.... what to lube this with? <br /><br />Petroleum Jelly- or will that break down the rubber?<br /><br />What can I use?<br /><br />Thanks!