You would think they would want to get a non-performing asset off their books immediately, but like @Troy Norwood said sometimes they sit for years without anything being done.  

Have non-refundable earnest money that keeps growing with contingencies in the original agreement and with each extension they ask for.Have a (right to continued marketing clause ) where you can kick out their offer if they do not perform.

@Jason Dillard   I agree with your premise in non appreciating  markets were its a given that appreciation is not going to happen at any appreciable rate .... in those markets your NUTS to buy anything that can't cash flow significantly and or you have bought it under market ( IE retail value) And it really depends on your ability to scale and run an operation.. you need a crap load of doors bringing in 200 a month to make any serious money  like a 100 or more.

On the commercial side if they have tax returns then we can usually go the non-bank route to get great terms.

@Eugene Lee  those rules were spawned out of the Great GFC... not germane to todays markets in most areas.you can though still buy in areas were there is more housing than people to use the housing and find those rules apply and even more.. those are what we call cash flow markets that's all they are all they will ever be ( in most likelihood) so if your going to invest there only reason to do it is to hit those 2% or better metricswhere we reside on the West coast we generally look for break even and make our big bucks on having our tenants pay down our debts and of course appreciation... you have most folks that live in the non appreciating markets and their mantra is  ( cash flow cash flow appreciation is only luck its not investing  LOL)  and you have those that have gotten stupid wealthy buying west coast assets that double or tripled in value in a 10 year time frame.. take your pick..

I gave the potential buyer two options, either they eliminate the appraisal contingency on the offer or they have their earnest money deposit go hard (non-refundable) after 10 days in escrow. 

Not sure what type of assets you have financed in the past, but I usually find better deals/terms with non local lenders.

You would first have to distinguish between performing and non-performing notes.  

For eg. a non-agent can buy a house for cash directly from owner bypassing MLS.

Are non-recourse loans in play here?