Wait ... do more than just "rinse." They need to be completely washed. I put new ones in a large strainer and flush the hell out of them. Otherwise, they will release a lot of dust and dirt into your solution.
They can be reused from grow to grow as well. Actually they can last for years. Just be sure, after each grow, to put them in your oven at 400 degrees for 30 minutes before reusing. This kills all the bacteria and readies them for the next grow.
Vi