Supermax,
Their site tells it all on
http://www.scottoiler.co.uk
I can't tell you how long chain&sprockets last yet as I ride way too little miles for that although I have been using this thing on my other bike for over 2 years already.
My experience and from what I've heard from many others that do loads of miles show me that it really works as advertised. There's not much (if any) sales-hype in the way they put it on their site.
I can make you some pics of how/where I've installed mine on the Busa if you want?
Keeping it on the lowest flow setting means there's no mess at all, increasing the flow towards the maximum will have some mess fling-off and in the Busa's case this might mean that some can get on the rear tire's edge as well, but increasing the flow above minimum is really only necessary when e.g. you're riding it in the rain, so normal in my country but I don't know about your area.
In general, the only mess you can have with the Scottoiler is from what flings-off around the back of the rear sprocket, contrary to whatever you can mess-up by spraying by hand in many other areas.
Please be aware that you need a vacuum connection, so either use the #1 or #4 vacuum connection at the throttlebodies after removing respectively the airbox flapper valve vacuum line or the PAIR system vacuum line or you'll have to T one of the many available vacuum lines on the Busa for the Scottoiler vacuum connection.