Take care of this problem by keeping everything you'll need for bathing in a small, easy-to-carry bucket. Fill it with all the soaps, lotions, oils, extra washcloths, baby brushes and whatever else you might need. Then when it's time for a bath, just grab it and go.
You can find buckets like these at most stores that sell household items or you can use a child's sand pail. That way, when your child has outgrown the baby bath, it can be used as a toy.
If you want to make it fun and help older siblings feel involved, you can get some colorful paint pens and let them decorate the bucket.
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