Honestly, this is the first time I've heard an actual chain oiler user say it's not messy.
I read up a bit on the Loobman which can be purchased for less than 23 english pounds and it is semi-automatic. One holds the button down to release oil to the system, which then is distributed by capillary action via a couple of flexy nylon fingers to the sides of the sprocket. Presumably, after some experimentation, one could gauge the amount of oil needed for their particular requirements. It's also apparently a thing to increase the size of the "feedpipe", which is the plastic tube running between the reservoir and the oiler head, by putting a series of "S" turns in the tubing.
If anyone is interested in more detail, here's a link to the maker's site.
http://www.loobman.co.uk/faqs.aspI find that I'm always more inclined to trust sellers that represent themselves with a web site that is NOT slick and polished. Makes me think that the product must have some merit, cause it's definitely NOT the sexy website selling them.
I'm not fond of the fact that the Loobman delivers oil to the rollers and the insides of the inner chain plates. I like to get my chain oil on the edges of the interface between inner and outer chainplates.