[koiom]

Read this:

http://www.advrider.com/forums/showthread.php?t=345397

those results are interesting but as one or two guys in that thread said.
WD40 is a penetrant.
although it has no effect on the O-ring, it has the potential to get past the O-Ring and dissolve the lubricants found within.

fwiw i think kerosene, a chain brush and toothbrush work a treat and cut through road grime a treat.

 

[koiom]

They look like they'd be a little bit impractical???

why would yo consdier the grunge brush to be impractical.
it's 3 sided brush get to all exposed sides of your chain in one fell swoop.
it doesn't get anymore practical than that