“When the rooms are very dirty, we use more water, more scrubbing, stronger chemicals,” Ms. Garibay said. “It’s very hard because we have a lot of pressure to clean the rooms on time.”

Hotels are still figuring out how to reduce guest room services. William D. Frye, an author of the book “Managing Housekeeping Operations,” published by the American Hotel & Lodging Educational Institute, described the change as “still in its infancy.” He said hotel management could do a better job of determining how long rooms would take to clean if service had been skipped for several days, adding that hotels that don’t find a way to adjust to the new normal may find themselves losing housekeepers to those that do.

Barbara DeLollis, a spokeswoman for Marriott, said housekeeping managers could assign extra help or extra time if an excessively dirty room was brought to their attention. Mr. Oh said that was the practice at his property, too.

Hotels are also encouraging guests to reuse towels and to have their bedding changed less often. With fewer linens to wash, hotels save money on laundry services and can reduce housekeepers’ workload. That can benefit housekeepers in another way: Changing sheets, including repeatedly lifting heavy mattresses, is one common contributor to repetitive stress injury, Ms. Ten Eyck said.

Since Americans, on average, change their own sheets at home only once every 24 days, according to MattressAdvisor.com, a review and sales site, sleeping for a few days on the same hotel sheets probably isn’t a hardship.

The incentives for guests to skip some services vary. The Mondrian South Beach hotel in Miami offers free coffee if guests reuse their towels. At Kixby, a boutique hotel in New York, guests who choose to keep the same towels for at least two nights receive 15 percent off their next stay. And at the Heathman Hotel in Kirkland, Wash., the front desk asks guests when they check in if they would like to skip room cleaning and linen changes in exchange for 10 percent off dining at the hotel.