According to Spotrac even with the dead cap hits the Raiders would save $6.8 million this year (not sure if that would change further into the season) and $1.8 million next year. They would be paying a player not on their roster which is a tough pill to swallow but it would make their cap situation slightly better, not worse. For a team possibly wanting to tear it all down and start over, and hopefully Adams himself putting some pressure on them to trade him to a contender, that isn't a bad outcome.
The biggest issue in my mind is you would need agreement from a coach and GM desperate to win enough games to keep their jobs next year. Unless Mark Davis himself steps in and forces the trade, why would they agree to do that?