Necromancer

I dont know what you mean by "Funk at its core is dirty and noisy", if you mean the RHCP's style, then yes, I consider the RHCP's are more of a Punk Funk/Rap Rock band anyway.
Artist like Lenny Kravitz, Prince, & Maroon 5, just to name a few that are classified within the Funk Rock genre are not dirty and noisy sounding, dont get me wrong, the RHCP's have done alot in helping to bring the Funk Rock genre more mainstream and I am not trying to discount the RHCP's music, I am only trying to point out that most traditional (Funk) is not noisy and dirty sounding as suggested.
But then on the other hand, you have Jimi Hendrix, (whom most consider him as one of the main innovators of the Funk Rock genre), what I find when most people are discussing the subject of Funk Rock, they mainly describe the Funk part and say nothing about the Rock aspect of the genre itself, would'nt Rock be where the noisy and dirty sound originates more so than the Funk aspect.