Goo:
Gelatin is a hydrophilic colloid. It is decidedly charged below 4.7 pH. It works as a shield for hydrophobic colloids. Therefore, hydrophobic colloids can be changed to hydrophilic and confer stability.
Aluminum chloride:
Provides positively charged aluminum chloride ions for adsorption onto negatively charged particles. Thus, the negative zeta potential decreases. When the right amount is used.