I guess you can wash them with what ever you want, but since your washing Puppy pee out of them... I wash mine alone
And you can just use regular clothes detergent on them. They will smell spring or rain scented to you but believe me, your dog will STILL smell their Pee on them! Their noses are amazing!
Wash in warm or cold water and tumble dry, just don't use Fabric softener, it makes them less absorbent. They are good for an excess of 300 washes.*
*Reclaimed pads from other companies are often sold because they have exceeded or are close to exceeding their wash limit and their inner materials will begin to breakdown. Commercial companies use very large machines to wash their pads and linens and they are very harsh on the materials which is why they turn over their inventory as often as they do. While reclaimed pads are an inexpensive way to try out washable pads, they won't have the lifespan that new pads do.