haha i agree with velvetee ( as usual)
dont mean to be disrespectful but i doubt u would feel the same if it were your own, i totally see where u are coming from, my partners daughter is 11 and i think things that really annoy me about her dont with my own,
i mean she goes the toilet, doesnt wipe!!!! doesnt flush and doesnt wash her hands, it winds me up something rotton!!!! my daughter always wipes, flushes and washes but if she didnt i very much doubt it would annoy half as much, tho i would constantly remind her to!!
basically my point is, if they arent doing it at home for themselves they arent learning and getting used to doing it so they will just act the same way at yours, they are both still very young, i mean my nephew is 11 and oh my god he has never lifted a finger to tidy anything, despite he mum constantly telling him to! what can i say men!!!
10 is a good age to start learning indepence, tidying up after herself, you could do a rota, where they have to do certain things before they can use the computer etc things like that, make it a rule and encourage them a bit more, dont pick dirty clothes up off the floor, only out of the wash basket, so if they leave them on the floor they dnt get washed and they have no clean clothes, they will soon learn to put them in the wash basket!!!!
well good luck