Opinion about to blocking EGR valve

Hi,

This is for your kind opinion about blocking EGR valve for my skoda octavia MK2 .I've seen a small oil sweating on the valve. I ask this about my Mechanic. Who have told me ,its not an major leakage and its just an initial stage .So when ever there is severe leakage, we could block the EGR through scanning machine. They are now doing for all VW cars including Q7 and other Skoda's .My Mechanic  doing works for all premium cars like VW,Skoda ,Mercedes ,Land rover BMW,Jaguar  & etc I would like to know about your experiences in this case