I know of one seed company that says to remove the strings.

In all of my years growing SSS, I've never noticed that they had strings. And, I let some of the pods get about as mature as possible.

All of them have strings. Stingless varietes may be less noticeable or hold a little longer on the vine. Just pick them when they are young and tender and you will be happy. Don't let them grow old on the vine or the stings will be noticeable no matter what the variety.