They do have flushing machines, and I have personally used them before with very little confidence that they actually worked worth a damn.
If you have ever blown out cooler lines you know how hard it is to get all the junk out of them, so exactly how is a low speed rinse going to get all that junk out of a converter with all the nooks and crannies they have.
Then you have Torrington style needle bearings and other critical surfaces as well as to consider.
How much damage was done to those surfaces, and would you want to risk a new rebuilt trans on them?
IMO a converter flush on a trans that blew up is only good for making a shop more money, and puts the new or rebuilt trans at risk of early failure.
