R' Gershon Seif wrote:
> He also told me that he's spoken with Rav
> Zucker who wrote the Chol Hamoed sefer and
> he's pretty sure that's how Rav Zucker
> learned as well.

Apparently, that's NOT how Rav Neuwirth learned it:

The Shemirat Shabbat K'Hilchasa 66:66 (that's not a typo!) says 
that "magavot mitbach" may be laundered on chol hamoed when needed. I 
think it is safe to translate that as "kitchen towels". His source is 
Mechaber 534:1 and Mishna Brura 534:4.

Akiva Miller