I dont think they can stop you BUT i would suggest you consider the following:
The smell of keeping them with your stuff.
If i asked hubby to take them home, im damn sure they would still be in his car the day he collects us to take us home - again the smell - oh and If he did remember to take um out of the car, the likelihood is they would be sat on the floor in front of the washing machine when i got back
and as someone else said, the meconium is very very dark and might stain.
it might be easier to use disposables for a couple of days imho