Yes! The strap comes attached to the bottom of the blanket through a nylon loop. by removing the buckle from the strap - you can easily remove the strap completely and secure it to the blanket for later use.
Yes, however to increase the lifespan of your blanket - we recommend hand washing or spot cleaning your blanket with a mild detergent. Drying your blanket in a hot dryer will have a rapid negative effect on the waterproofedness of the blanket and we do not recommend it. It will also cause the stainless grommets to show signs of wear sooner. If the blanket really needs a deep clean - we recommend machine washing it with mild detergent, cold water, gentle cycle. Line dry.
Don't see the answer to your question? Ask the project creator directly.