An aerosol system or method for mixing first and second materials comprising first and second container assemblies and a coupler. The first container assembly contains the second material and a propellant material that pressurizes the second material. The second container assembly contains the first material and at least a partial vacuum. The coupler comprises first and second coupler connecting portions and is arranged such that the first coupler connecting portion engages the first container assembly and the second coupler connecting portion engages the second container assembly. The propellant material and the partial vacuum in the second container assembly cause a portion of the propellant material and at least a portion of the second material to flow into the second container assembly to form a mixture in the second container assembly. The propellant material within the second container assembly forces at least a portion of the mixture from the second container assembly.