There was one gal from here who was going to try it. At the time a search of the internet showed a fair amount of issues with it. It appeared that the emails led to a suggestion you 'buy a list' of places you could apply to. Some of them had several layers of purchases if I recall correctly. Do Google it, especially by purveyor name, before you open your wallet.
There were, indeed, a bunch of mortgage lenders who required borrowers to continue to pay mortgage insurance even once their equity was above a required minimum. There were court cases about that 5-7 years ago if I recall correctly, and banks were required to return the excess 'promptly'. I suspect that led to a possibility of home rebate processors, but those days would be long over. I do a lot of rebates of both an on-line and mail in basis and the processing comes out of Young America, MN, Miami, FL and San Antonio, TX. I seriously doubt that my paperwork or computer input is shipped off to home processors and then back to a central location to print and mail the checks. And when my rebate is 79 cents, just how much would a processor be making? Yes, of course, there are rebates that are a lot larger, but I can't imagine it is feasible to check the stuff, ship it out for 'processing', ship it back, review it to make sure the processor did it right and then cut the check for mailing. Far more efficient to have one employee open the envelope and check the stuff, one double check and process and then queue it to have the check cut.