My rabbit specialist vet has said that it's not uncommon for buns to eat newspaper and cardboard and that a little shouldn't harm them...all that tearing makes such a wonderful sound to little bunny ears! It's in a bunny's nature to chew, it helps keep their teeth trimmed down, so give them something else to chew on such as branches from an pesticide-free apple tree. They also chew when they are bored, so you might get them some toys before they start on your furniture. There are all kinds of free toys that bunnies love...empty toilet paper rolls, a empty margarine tub, a golf ball, and empty cardboard box turned upside down...put in 2 doorways so they don't get trapped. Some cat toys work well too. Also check the House Rabbit Society webpage for all kinds of fabulous bunny-related issues (best food, health, behavior, etc) as well as a link to pet suppliers specializing in bunny toys, hay, and so on. By the way not all fruit tree branches are good for buns so don't give them just anything. Most pet stores sell wood chew toys but they are painted, which is not so good.
Bunnies groom themselve constantly, so what your little guys are doing is not unusual. I wouldn't bathe them unless they get incredibly dirty or soiled.
I have 5 buns and have volunteered at a rabbit sanctuary for 4 1/2 yrs now so I've pretty much seen it all...just in case you are wondering if I am leading you astray!
Good luck with your new best friends. Bunnies make incredible pets and, furthermore, you did the right thing by getting a pair so that they are company for each other. My very best wishes to you all.