"They promise"?
You're kidding, right?
This is just another variant on the (far too many) useless "escape / relief / exit / rescue" operations out there preying upon timeshare owners desperate to part with something they don't want anymore, but cannot sell. Take a step back and think of it this way --- once you pay upfront money to
any such parasitic operation, what motivation exists for them to do
anything more than just say "Thanks"? After all, by then they would already have all the money they would ever get from you anyhow, firmly in hand (or in the bank).
Also, consider the possibility that the "Compliance" entity and the (alleged) "third party escrow company" could actually all be the very same people, just wearing different hats and / or using different addresses for different parts of their "operation", or perhaps they really are distinctly separate entities, but operating in cahoots with one another and, by agreement, sharing portions of the "take".
Last but not least, this could be an operation which (if they actually do anything at all) just dumps the ownership into a phony LLC, created solely to evade contractual and financial responsibilities. That is fraud (and potentially a criminal offense). Do you really want to risk (and even pay upfront money for) being any part of fraud, knowingly or otherwise?
Are you comfortable with any of the above possibilities? Probably not. My advice is to not just walk away, but
run away. Any upfront money you part with will surely be gone forever and you will
still ultimately remain the owner of record for whatever it is that you are seeking to get rid of. Put the checkbook away and pursue other far more legitimate (also free or low cost) options such as inquiring about "deedback" directly to the resort and / or attempting a Bargain Deals give away here on TUG. I think RedWeek may have a similar "give away" venue. If you pay upfront money to any unknown entity of dubious legality and questionable intent, you do so at your peril.
Just my own personal thoughts and observations, to consider or reject as you may see fit; it's your money.