Walmart's Night Crawlers (adult and baby) are parasite free, and are safe to use with larger frogs. Many members here have used WNC for extended periods of time, and will tell you they have never had any problems resulting from it.

I am not exactly sure about what size frogs you have atm, but nutritionally, Walmart's Night Crawlers are great! Just make sure they are Walmart Night Cralwers (I think it is something like DMV brand...DM something). Malcolm eats smaller pieces of Night Crawlers, because he gets really freaked out about the entire worm. If you think your frogs are big enough, it should be fine.