Wash me, watch me
The second hand couldn’t even clock me
Literally he’s saying that he’s so fast, that the second hand on a clock isn’t fast enough to keep up with him.
But also there are additional puns at work here. Unrelated to time, “the second hand” could refer to “the other hand,” as in the common phrase “one hand washes the other.” To “clock” someone is to hit them with your hand. So the second line could mean, “The other hand couldn’t even hit me,” and even though that doesn’t make much sense contextually, it’s worth noting.
To help improve the meaning of these lyrics, visit "Rainbow in the Dark" by Das Racist Lyrics and leave a comment on the lyrics box