Spoke prep is good stuff, I use it as well.
I dip one spoke into the little jar of the suff, but only so 2/3 of the threads have it on. The amount on that spoke is good for 5 or 6 spokes, so I take one spoke and it next to the one which I dipped into the jar, so the compound spreads to the other threads. And just do that over and over, let it sit for a few minutes too