nope, i wash my rat's towels along with my own towels. they all go in dirty, and they all come out clean. i use unscented detergent, and none of my personal towels end up smelling like rat pee. they all smell the same after they gete washed. if you are worried, do a separate load of "rat laundry;" i highly doubt it will "contaminate" your washing machine
that what I told my dad. he doesnt want me to get a rat in the first place because he thinks they are gross, because he thinks of sewer rats. but He would be the one paying for the bedding. so its either like $40 a month or $15 for two towels that can be used untill the rats destroy the, if they do. Have any ideas on how to convince him to letting me us the washer. I dont see how it would make other things smell. it a washer, it washes things.
tell your dad that washing rattie bedding in the washing machine either alone or with your stuff WILL NOT KILL EITHER THE WASHING MACHINE OR YOUR/HIS CLOTHING. the whole point of detergent is to get the clothing clean, and it works equally as well on people clothing as it does on rattie bedding. after all, when he was a kid, i bet there wasnt disposable nappies/diapers/call-them-what-you-will around, so his mother, your grandmother, would have washed them in the washing machine... same deal as washing rattie bedding.
as for using towels, go to a second hand store and buy them for a couple of bucks each, maybe even less. you will still have to wash the towels as they will stink otherwise.