get sme good quality black wire crates, nothing with a wire floor, the only gaps in a good crate are between the bars and the long one the botom tray slides into and any boxer that can squeeze out of a 2" space needs to be reocrded for fame!
making the dogs outside dogs is NOT the answer...youd be punishing the dogs (who are pack animals and just want to be with you) for their lazy humans
im sorry your having to deal with this, sounds like your the only adult in the house...i can tell you ow my father would never put up with that kind of behaviour from me my siblings or my mother...
if they cant handle the dogs they dont deserve the dogs, so rather than outdoor living id consider rehoming as an option, kinder on you, kinder on the dogs in the long run because ther eobviously not getting what they need in that house, at the very least it might be worth your dad rehoming the boxer bieng its a pup and easier to find a home for...and before your sister complains that its HER dog...shes not looking after it, shes not training it and shes living in his house...
legally the dog belongs to whoever name is on the paperwork and if no papers the dog belongs to whoever pays its vet bills...but its your dads house soo....
other than that id say it sounds like this is up to you...
personally id go on a cleaning strike, keep the dogs out of your room and keep your room spotless but otherwise the rest is up to them...
the only worry with this would be folks taking it out on the dogs and its REALY not their fault.
they will keep going to the bathroom in the house because there not being walked and without through enzamatic cleaning (which honestly id thing the carpet is long beyond any help the enzamtics can offer if the urine is in the underlayment no amount of natures miracle will help) the carpet smells like potty zone. plain and simple.
crate trining is going to be your frined if YOU want to try and make this work...when the dogs cant be supervised 110% they go in their crates...take them outside to potty regularly (as often as possible at first) and if you stay persistent they WILL learn (cockers are icnredibly eager to please their people..
these dogs can be trained i swear, its just a case of bad people and im sorry you have to take the brunt of that.
but please dont give up on the dogs by just putting them outside...
not to mention i have a feeling if the dogs arnt in the house making a mess, something else would come to take its place, be it more animals, or junk ect.
training can and will work, or it might be worth trying to rehome the puppy at least.
good luck.