How did your gecko survive during your weekend? I'm going on a very short family holiday, and I can't take my gecko with me. So, I don't know what I should do.
Honestly, I'd err on the side of caution here. Mold can produce toxins that might not be good for your geckos, even if the mealworms eventually get rid of it in their bodies. It's better not to take any risks with your pets' health, right? I'd suggest cleaning out the farm as soon as possible...