A salary dump is a trade whose point is to shed a contract rather than to get talent back, usually sweetened with a draft pick for the team that absorbs the money.
In HoopSim a salary dump needs a partner with cap space, because a team over the cap cannot take in salary without sending some back, and there is no cash in trades and no trade exception to absorb it. A team under the cap can take back up to its cap room. Picks carry no salary, so a pick is the natural sweetener, within the Stepien rule and the three-year limit. AI GMs weigh the dump against their own plan: a rebuilding team with room is the likeliest taker. The alternatives are cutting the player (dead money) or stretching the cut in the offseason.
Rulebook: Salary matching. Related: salary matching, dead money, cap space.