I helped write the latest book on dielectric constants of materials never ventured before and it's safely stored in a fire proof safe at GRC's office who's doors are secured better than Fort Knox.
Of course you'd like me to specify the range of frequencies that are tightly specific in range of materials containing hydrocarbons and I'm sure you'd like me to specify the center most effective frequency specific to such materials but sorry Joey you will never be able to steal that information anywhere. There is no book or information available on the internet about it either as only a few people have the black box to discover it and money to invest in that black box. It's just killing you to know it.
And as usual you are way off base on power and efficiencies but I take that you're fishing for that information too.