As with any baby materials, cleaning is a critical component because babies will be babies and make a mess of everything they come in contact with. For any swaddle blankets, I recommend reading the instruction labels sewn into the side of all the blankets. You will need to see if can wash it in warm or cold water. For some it might not make a difference and in that case I would prefer to wash it in warm water to help remove more oily components that stick to the swaddle blankets. Warmer water is better at removing oily and greasy stains that might stick to the swaddle blankets.
I like to use Dreft as the detergent for cleaning my baby swaddle blankets and baby clothes. Dreft is a synthetic detergent without any harsh chemicals or bleach. With you no harsh chemicals in the washing, you will not have to worry about your baby developing rashes or getting skin irritation when you wrap your baby in the swaddle blankets or clothes. This also makes Dreft a great product for babies with allergies as fewer chemicals, dyes, and perfume that can potential trigger allergic response.
Some babies might be less sensitivity to detergent, so I recommend washing some clothes with your standard detergent and have your baby wear them for a week. If no irritation or response occurs then your baby is probably no as sensitive to the detergent.
As for drying your baby swaddle blanket, I do not recommend using fabric softener. Most fabric softeners have chemicals to produce the nice fragrant smell on top of the chemicals used to soften fabrics. However, you can test your baby’s sensitivity to the fabric softener you use. If you don’t get any allergic response within a week then your baby is probably safe.
Once dried, the swaddle blanket is ready for another round with the baby.