The Mattress Safe's Sofcover Superior Total Mattress Encasement - Twin Plus+ has not been tested for lice, they are only Bed Bug certified. Due to the size of adult lice and the nymphs, the manufacturer is uncertain if the encasements would be able to contain the insect.
We recommend the following treatment:
Clothing, pillows, blankets and sheets should all be washed in hot soapy water and dried for at least 30-40 minutes on high heat in the dryer. Non washable items (stuffed animals, dry clean only clothing...) should be put in the dryer on high heat for at least 30 minutes. Any other items should be sealed in bag for at least 7-14 days.
Carpets and other flooring should be thoroughly vacuumed and the vacuum bag sealed in a plastic bag and thrown away. Furniture can be sprayed with Sterifab. Sterifab is an alcohol based product that includes a synthetic pyrethroid that is safe to spray on furniture and mattresses. Sterifab dries in about 20 minutes and does not leave any residual on the surface that is sprayed.
Using a liquid insecticide around the home:
There is no reason to spray a residual insecticide around your home to treat for head lice. The adult head louse cannot live more than one or two days with out a blood meal. Nits cannot hatch if they are not on a human host, because their temperature cannot be maintained properly and the nit will not be viable.