ADVISE PLEASE!!

Hi, my name is Dave, first of all. So, i bought some silkworms from mulberry farms. I own 4 VERY high end leos and wanted to put them on a more specialized diet than superworms...maybe something that doesnt bite and is better for them, so naturally i picked silkworms. First- was this a good idea to feed them exclusively silkworms as a set diet, or should I have taken a different approach and fed them a variety? next- I had recieved them and mullberry food in a package, and by the way hated the whole having to deal with transfering them into my container, but thats irrelevant I suppose. I put them in a deep container with an egg carton and food spread on the botton (container had holes in top) and they seemed fine. In a matter of an hour there was what I thought was fecies EVERYWHERE! Further, I had tried to clean out the container which was also a pain, and replaced food/etc.. and it just wouldnt stop getting way too messy. long story short- this was for only 100 mixed size silkworms, and at least half were dead within the week, so they all were dead and it was a waste and a travesty. Any advise on this? A different container? Something I can do to keep them very healthy? Tp rolls in the container will help? Please I need your advise pronto! haha. I just ordered 50 medium from the same people and they are on thier way now and I dont want them to die or even be miserable. Thanks again....I'm a newbie to silkworms.