I absolutely love my EX500s.  Balanced, yet with full bass in the mix.  Excellent imaging as well.  Love 'em.  

@Bonsai, thanks for the update.  Now I know a bit more before I decide to dive in.  And @Jack, I agree.  But since I already have the plugs, and they're just leaking a little, I wanted to see if there were any options before buying a new pair.  

Hi,   I'm interested in trying this on my old Westone musician's plugs.  What kind of silicone are you using.  Like a household silicone sealant?  Then the vaseline doesn't mess it up?   Thanks for the info!