You can fairly easily release the catch by removing the grilles carefully. Buy a whole new catch, grease is just a temporary fix, it's one of a few parts that will fail on a mk5 at some stage.
( I can half understand your caution guys about thieves getting tips etc, but honestly, they really aren't arsed about your paintwork....want something from under your bonnet? A screwdriver and tin snips, straight in, same with door locks, want your RNS 510? No bother nearest rock through your window, these cars are precious to us but not to them)