See about a second walk through. Make it know you have concerns about the property's condition. Let the agents do some talking. If you still get a mess, consider a demand letter and if necessary, a law suit. Get some photos, keep your clean up receipts, and if the sellers don't make it good, think about small claims court. You can do it yourself.
Here's the thing - nobody can force them to clean up. End of story. You can beg, bribe, cajole - but you can't force them.
You probably can't extend closing without their written permission, not to mention the lender's.
This doesn't mean your agent shouldn't go to bat for you - but, realistically, it's the seller's responsibility, and their choice.
No Realtor can speak on behalf of a sales agreement confer to your agent.
Lynn911 Dallas Realtor & Consultant, Credit Repair Advisor
Read your contract carefully.
With our normal TREC contracts, the house needs to be in the same general condition as when you contracted on it. Look at 7D under NOTICE To BUYER and SELLER.
There are lots of solutions, so don't get too tied up with a green pool. Maybe a credit at closing from the seller to cover pool cleaning and house cleaning will suffice.
While some houses come sparkling clean, the standard is only broom clean.
Ask your realtor for solutions and advice.
For example I have heard buyers say they're not closing until X is done.
In the end you may have to go with it.