And....as I am too lazy and/or tired to clean every day, I never have (bar the first time I suspected worms, and I was pregnant and utterly paranoid ). I have changed and washed all sheets, towels and PJs, hoovered, cleaned bathrooms, and repeated two weeks later with second dose. In between times, just careful with hand washing, wearing of PJs and pants at night, short fingernails and I cheat and give an extra dose of Ovex after 3 weeks as well as 2.
That said, I've never actually seen a worm - just had episodes of very suspicious itchy bottomed nail biting 6 year old - and would probably go into cleansing fury if I did, as I am a bit phobic about things with no legs