Isn’t not following the intended purpose of the sign part of what ruins it for everyone else? Do they really have to make a sign that says it in more detail?
I wash my saddles pads at home (and I wish I could take them to laundry because they have the bigger machines which would get them more clean), and I find that no matter how much hair I brush off them (during shedding season) that there is still a mess inside the washing machine.
I do hope you wash an empty load and wipe out the machine when you are done.