5% is actually a bit better FYI. Good info though.They dont have to be frog free, I quite often will sell cuttings of plants that arent frog free when people ask for specific plants. However, when selling plants you should note whether they are frog free or not because people prefer frog free or to know that they need to clean them. If the plants have been in with frogs there is a chance that they could harbor diseases, thus when received people should clean them.
It is usually recommended to clean with a 10% bleach solution and then wash extremely well.