No, they are not. They present a high risk of impaction, especially to younger beardies.
I ran out of crickets once, and while I was waiting for my order to come, I fed Budo a few too many mealies, and he became minorly impacted. 30min baths daily, syringe-fed babyfood daily, plus massages and time on the heat pad. And a lot of worrying. And he was only minorly impacted; it can get a lot worse than that. Trust me, mealies are a waste of money and a risk to your dragon's health.