You don't really need the eraser as a separate application. Just use your choice of brush and pick a dual brush setting to suit. Save it as a tool preset for future use. You should be able to stroke a path with that without any issues, or you could just free-hand it.
I tried the dual brush several times to see if I could get this effect, but I couldn't get it to work. If you could share a step-by-step, I'd very much like to see.
You can also approximate the look with a brush that has the dash and dot, but angle jitter won't bend the brush, only rotate it, so you wind up with a sort of faceted line. At least, that was the behavior last time I tried it, but that may have been as far back as version 7.0. In any case, I'd still rather do this kind of thing in Illustrator than PS.
Here are some effects you can get with a simple round brush by adjusting these settings.
Edit: This isn't a dash & dot, just dash or dot. But I'm pretty sure you could get a dash & dot by creating a brush like what you did with the eraser technique above... two vertical lines but vary the width... then set the dual brush settings to refine.
Here's a makeshift dot dash line using a dual brush on top of a circle-in-circle brush. I stroked a path with it, then removed the dual brush setting in the panel so you can see how the brush spacing is set on the base brush. Probably not as nice as Illustrator, but it works in a pinch.
Ah! Now that's and interesting approach! I'll have to try to find some time to experiment with it sometime soon. I really do need to delve into the brush settings a bit more, anyway.