i was wondeing if anyone has a list or any idea of the heaviest/densest liquids/gels which are harmless and therefore require no saftey equipment or hazard warnings or health n saftey worries. the main aim of the substance being to add weight whilst still being pliable?? and to be at room temperature! ideally it will be a gel so as to not create imbalance when movement occurs ie by movemnt of the substance which is what happens with liquids when movement occurs.