Whilst browsing the Bailey Direct site for something else to waste my money on I came across Thetford Cassette Cleaner.
No this isn't for dusting off your old Peters & Lee audio cassettes but for giving your khazi the once over.
Now cleaning the inside of the bog is not something I have given a great deal of thought to but at about £7 or so per litre at 300mls a treatment it wasn't going to break the bank.
It is easy to do and I must admit as far as I can tell by peering through the hole it does appear cleaner and fresher considering what has been through it.
Thetford Cassette Cleaner
So if you have nothing to do one afternoon you could do worse than turn your attention to the inside of your toilet.
Your bowels will thank you for it.