This was a tricky song to learn to sing and play at the same time. I probably first tried it on cello in 1995. I was able to apply a practicing breakthrough from my recent early jazz work to this song. The key is organizing the pizzicato rhythmically. Previously, I was using two fingers (1st and 2nd) to pizzicato “as it comes.” In other words the two right hand fingers simply alternate, regardless of the rhythmic function of the notes they are sounding. I learned however that it is better to assign the fingers a specific rhythmic function: 1st always plays downbeats, 2nd always plays weak beats, “on the and.” The change has helped with feel and rhythmic awareness when adding the syncopated vocal as sung by Kurt Cobain to a bassline.
Here’s a PDF for learning Come As You Are that includes a preparatory exercise to help organize the right hand pizzicato rhythmically.