I know that a lot of people who sell roaches breed on Dog/Cat food and broccoli exclusively, then they sell them off. Therefore, I wait a couple months before feeding them to my chams., just to be safe.
I breed my dubia/lateralis colonies and crickets with Colard greens, dandelions,Kale,carrots,oranges,apples,melon and oats. The feeders love it just as much and it is very cheap. Everything I have read says it is safe also.