OK, so there is an in-home business and then there is a MLM. Two very different things - an in-home business takes many forms (ok, MLM is one kind, but not great), but there is a set work schedule and budget and income. If you don't stick to the work sched, especially, it won't work (I learned this from my own experience).
MLM on the other hand requires investment up front and then often continually putting money into it, too. My general advice when you see an MLM is RUN AWAY. Sure, some people make money at it. The people who signed him up are making money off him every month, as well as their uplines. But to make good money, you have to get more people to sign up and buy the stuff for themselves, and get them to sign people up too. I just hate the whole setup - you're not selling a product, you're selling a "business" - and that's just not right....
Anyway, if he isn't willing to put in the time to make a business of any kind work, he's just throwing his money away. And, in my honest opinion, this MLM isn't worth it. I've heard of it, and looked into a lot of them, always very skeptical, and always decided I didn't like them, and really only a very small percentage of people make a lot of money, and a lot of people barely break even.
So, now that you're where you are now, I would suggest sitting down with him, and putting your foot down. Tell him he's had his chance, it isn't working, and you refuse to keep throwing away your money on a product you don't need. Tell him it's time for a wake up call - if he was an employee with this work ethic, he'd have been fired long ago. Until he's willing to actually work, he has no call being self-employed. And again that you hate the business and don't want to spend any more money on it.