I'll answer to the question you should have asked but didn't: how can you reduce the amount of the black dirt flying around?
There are huge differences between chain lubricants. Try a different brand of chain lubricant. Best chain lubricants are in a spray can. They are thixotropic. Do note that not every chain lubricant in a spray can is thixotropic, and those that are, don't usually specify the magic "thixotropic" keyword. If a spray lubricant is not thixotropic, it will work extremely poorly and fly around all the time.
If you spray a bit of a thixotropic lubricant in a small container, you will see it's that it is quite liquid. However, if you leave the lubricant to settle, it gradually becomes very thick and not so easy to flow. Now, if you stir the settled lubricant, it starts to become liquid again and will flow easily.
Did you remember to remove the excess lubricant from the chain immediately after applying the lubricant? If not, this could also explain the black stuff flying around. Note that if the lubricant is thixotropic, getting the outer layers away might prove a bit tricky unless you do it immediately after applying the lubricant, and some amount of some solvent applied to a rag could help you.
I'm not entirely sure if these hints will stop all of the gunk from flying around, as the lubricant needs to be somewhat liquid to not cause additional resistance. But, however, you should be able to reduce the black stuff flying around to a minimum.
Disclaimer: I have no experience of motorcycle chains, but for bicycle chains the thixotropic motorcycle chain lubricants work well. I presume they work well for their intended purpose, motorcycle chains, as well. Yes, I do use a motorcycle chain lubricant on a bicycle; most of the bicycle chain lubricants marketed are pure crap.