WD40 and Petroleum or solvent based liquids with play havoc with the X or O rings and cause them to swell and eventually break up.
Parafin (or Kerosene if you speak Am-er-ri-can) is oil based and therefore won't harm them.
I favour using a rag soaked in some to wipe the crud away and then re-lube after.
Regina Chains have this to say:
http://www.reginachain.it/eng/use_an...how_to03.shtml
And Sprockets Unlimited say this:
http://www.sprocketsunlimited.com/Chainmaintenance.html
As for what I am running on the Monster a D.I.D. VX X-ring chain coupled with Afam sprockets front and rear (gone up two teeth on the rear though).
Bought from the lovely people at Bike Torque Racing through their ebay store who were happy to up the teeth on the rear at no extra charge and who I have dealt with for many years now and offer a great service.
http://www.ebay.co.uk/itm/Ducati-900...item1ec9829291