You are responsible for keeping the totes in the same condition in which you received them in, but no you are not required to clean the totes before returning them. No animals are allowed in the totes, or there will be a charge of $2 per tote to your credit card on file if we find a lot of animal fur. Also, do not leave these totes outdoors as this will create lots of dirt. Excessive amounts of dirt, mean extra cleaning for us. There will be an extra $2 charge per tote to your credit card on file should we come across an excessive amount of dirt to clean. As far as cleaning the totes out, we use our eco friendly cleaner to get them ready for the next customer. They will be sanitized and as good as new. Just as long as you return them to us free of items and without dirt or pet dander, you are golden!