Mike,
Short answer, no, not as a matter of course, but then we don't scrub every domestic carpet either. When you've got over a thousand yards of carpet to clean in three and a half hours, there simply isn't time to scrub every and besides which we use RX20's which is mechanical action within the cleaning process. The difference between cleaning carpets on cruise ships and similar facilities on land is that the carpets on ships are of a very high quality and are cleaned every year without fail. Time pressing or not, we do rotary scrub some areas, particularly in the restaurant / galley entrances where they tend to get quite greasy. This is why we have scrubbing brush attachments for the RX20's so we can switch heads in a few seconds and not have to hump another heavy machine onto the ship.
Simon