I've looked at that "parasitic stuff" for years now, and I'm convinced it is 98% nonsense. You'd be better off leaving your amplifier alone.
N7WS also made measurements, and concluded the same. Eimac and a dozen others (including the retired chief engineer of Collins Radio)also disagree with it, and pretty much dismiss it as "bolognia".
For actual measurements and a demonstration of what causes arcs and failures you can see:http://www.w8ji.com/Amplifiers.htm
Just write off the few bucks you spent to experience, and don't fix something based on false science.