I've also
been guilty of waxing my washer and dryer.
Then I got step children, who used the tops to apply stain pre treat to their garments, be careless with detergent, bleach, etc. Even as I placed worn towels on top of them.
One tires of preaching, and cleaning up after them. The more you do, the less they care. You can't watch them 24/7 unless you can stay home.
They had more pressing responsibilities like studying, playing video games, etc.
Heck, I was glad they at least washed their own clothes.
Now our daughter has her own family, and washer, and has discovered she needs to keep it clean, or mold and guck collect in and around the dispensers.