I have to say I tend to agree. What point is there adding such a word? It’s basically slang and probably localised to Australia. Do we really need this word added to the lexicon?
Jacki, surely you've noticed that we have no objection to slang here. In fact my spirits lift when a slang word is suggested, because it may be a word that's regularly used, but hasn't made it into our word list before, simply because it wasn't around or was little known back when the list was compiled, 20 plus years ago.
It turns out we don't actually have
skanky in our list let alone
skankiness.
Skanky can be applied to an object, meaning dirty. An example of this sense of the word appeared in this forum back in 2007, when Linda wrote about changing out of her "skanky jeans". However the word is most frequently used about women, with various disparaging meanings: unattractive, dirty, sleazy, promiscuous, etc. It can also, less disparagingly, mean attractive or sexy, although this is noted only by Green's Dictionary of Slang.
The word originated in US Black English, according to Green's Dictionary of Slang, but is now used around the world. Jacki, if you had the impression it is an Australian term, that might result from recalling that Australian politician Mark Latham called a newspaper columnist a "skanky ho" in the early 2000s.
Skanky has been around for quite a while, with the OED quoting a couple of examples from the 1960s. But its use became more widespread this century. An early example from network TV was in a 1991 episode of
Roseanne:
Man, the way her luck is going, I wouldn't be surprised if some irate mother of three jams a skanky dog down her throat.
A much more recent example is from the
Liverpool Echo in January this year:
A police officer who called a man a "skanky f***er" and "scum" after tasering him has been granted early retirement.
This illustrates that the word can be used of a male, though this seems to be rare
The original suggestion,
skankiness, is acknowledged by Collins, as you say, RTT. Here's a usage example from
Independent Online in South Africa in 2012:
Bucie is a talented musician who has a fabulous mixture of insanity and just the right amount of cheeky skankiness to make her a potential superstar.
I'll add
skankiness and
skanky to our list, as rare words.