Your H needs to tell his family that while they are living there they need to clean up after themselves period. Did your H have rules and a talk in place before they moved in? I know for the most part we like to think its common sense to clean up after yourself when in someones home but unfortunately it isn't so.

Your H needs to sit them down and let them know that you both work and are busy with hectic lives, they need to clean up NOW.

I can at least help with your dog poop issue.

Poop on the lawn, especially with little kids, is a health hazard and you should NOT feel guilty telling them it needs to be removed ASAP (that's AS SOON AS PRODUCED). It's a health hazard, plain and simple. The rest of the mess, maybe not, but you shouldn't think twice about reminding them your kids play in the grass so you're just worried about the hazard. Just make it about what's healthy and that way it doesn't have to get personal or negative.

Maybe telling them this much will provoke them to be a little more courteous in the house too.

I really am shocked when people leave dog poop anywhere considering the hazard of it.

How rude.  I can't imagine living in someone else's home and not offering to help clean. Seriously?

The direct route is best: "DH and I clean on Saturdays - please let us know what chores you plan to do next Saturday, as we need your help in keeping the house clean."

Don't be afraid to be straightforward with them. DH should tell them (and if he's won't, then you do it) that you and DH live differently, and while they are welcome in your home they need to be more considerate of how you and DH live. Give them specific expectations about keeping their stuff picked up, helping with chores, cleaning up after the animals, etc. Are they at least buying food or treating you and DH to dinner out now and then? 

You are becoming resentful and exhausted because you are too afraid of confrontation. Take a deep breath and tell them what you need from them.

Unfortunately...the easiest and less stressful way to deal with these things is up front.

When people say they are coming to stay for "a couple of months".. that period should be clearly defined.. and agreed upon by the both of you.  60 to 90 days should be plenty of time to find a home.  If they are looking to rent.. it can be even quicker.. finding a place to buy.. well... that could take a longer time, depending upon the market in your area.  If it is a longer term process.. they should be looking for long term solutions that don't involve staying in your family's basement!

I am assuming they are not paying for anything while they are there.. not the extra cost of utilities.etc.. Perhaps they buy their own groceries.. but I am guessing he was being mr nice guy and didn't want to charge them.  But this is costing your family money.. more showers.. laundry.. etc..  Also, if they were to pay "rent".. you could hire a cleaning service to help take care of things.

But, I get it.. extra people.. even not particularly messy people means more stuff around in general.

Your husband needs to deal with this directly.. they are his family.. you can sit there beside him and make sympathetic facial expressions.

topics for him to discuss.

1.  We enjoy seeing you here.. but we are wondering what the next steps are for you.  When we started out it was going to be a couple of month.. we are now at that point... and so we can plan things ourselves.. how much longer do you anticipate needing? 

2. I know it isn't comfortable for you guys either.. it's hard being all packed in here and when we just though it wasn't going to be very long.. we didn't really think much about changes to the logistics of the home.. but now.. I think we need to work up a schedule so that everyone takes part in the house and yard work around here. 

3.  It goes without saying that we should all be responsible for our own things and messes but there is also daily and weekly stuff that needs to get done too.  We are going to go ahead and draw up a schedule so that we all end up having an equal amount of responsibility.

4.  Also, while it's not really about money.. if you think it would work better, we can hire a cleaning service to come in a couple times a week instead.. and at this point.. I think we need to get a little bit of compensation to cover costs like that and our higher utility bills etc..

Again, we have loved having the chance to see you all more and catch up.. but it is starting to become a bit more work than we originally thought.. and we are hoping you understand why we are asking for some help from your end to make things smoother.. and also figure out how much longer you think you need.  Not trying to kick you out.. at all.. but obviously I'm sure you are anxious to get back more of your privacy too.

"Pick up your shit and pick up your dog's shit. Please."

A free hotel with maid service, nice! When can I move in?  

All kidding aside they are probably just slobs in their everyday lives. I'm sure their own home looks like a hoarder home.  I would have the come to Jesus meeting with them about keeping the space clean and setting the move out date up a month or so.  If possible do this as a couple w/DH leading the discussion. It should come from him since it's his family.  In the meantime emply the "Box" method. Anything they leave lying around in the common areas gets thrown in "The Box", including their dishes and nicely wrapped baggies of dog doo.  

You've got to speak your truth and set some boundaries in your home. Something the truth is hard and boundaries are firm. There may be some inevitable hurt feeling not from your doing but it's because the IL's are freeloading slobs.