Safe and responsible disposal of aluminum chloride? This answer affirms that reacting aluminum with HCl is a (seemingly convenient) way to produce hydrogen for use in other experiments, but the byproduct, AlCl3, is rather nasty. What's the best way to dispose of it? My naive guess is that reaction with baking soda would produce carbon dioxide and aluminum hydroxide, which would be fairly harmless. Is this correct?
Sure, you can react the $\ce{AlCl3}$ with $\ce{NaHCO3}$ solution, and you'd also get $\ce{NaCl}$, in addition to $\ce{CO2}$. 

Though $\ce{AlCl3}$ is toxic, it reacts readily with water, forming the less toxic chlorohydrate (used in antiperspirants!), and the baking soda should leave an innocuous sludge, safe to dispose of in a sink.

N.B.: The reaction is exothermic and bubbly, so use care when mixing in the $\ce{AlCl3}$ to avoids spatters.