Per Coon:

So let's do some math. Suppose Houston dumps Lin & Asik with $0 coming back. They renounce Daniels, Garcia & Hamilton. They waive Casspi
...Beverley, Covington & Powell. They keep QO to Parsons & Capela's draft rights. They have Dwight, Harden, Jones, Motiejunas & Canaan.
..With that configuration, they can give Bosh $16,427,992. Pretty short of his $20,644,400 max.
So let's renounce Capela & Parsons. Cap room rises to $19,279,451. STILL short of a max offer, and they don't have rights to Parsons.
To keep Parsons' rights & still sign Bosh to max, they have to dump another $3,732,744 in guaranteed salary. That's Jones AND Motiejunas.
So to get Bosh at max AND keep Parsons, Daryl Morey just needs to dump Asik, Lin, Jones AND Motiejunas with no salary coming he other way,
...along with throwing overboard everything that's not bolted down.