1- Dreaming of wax is a great deal to do with the pliability that we are able to achieve in our lives. We need to be able to be malleable, to be moulded, perhaps by external events. We should be prepared to give way, but also to be firm when necessary.
2- Wax can also to be taken to represent insincerity.
It is something that is consumed by the flame for instance, of a candle - and therefore can be moved and changed into something else with qualities that it did not initially have.
3- Wax is symbolic of the need for spiritual pliability, and the desire to move away from rigidity.... Ten Thousand Dream Dictionary
Sludge has two opposing interpretations. On one hand, it symbolizes dirty and undesirable aspects at moral and material levels. Dreaming that you walk through a muddy field signals the dreamer’s difficulties in real life.
If you dread getting stained by mud it indicates fear of becoming involved in matters that are unpleasant or turbid. In addition, clay combines soil and water.
It is a soft and malleable material, suitable for the manufacture of household utensils and for the development of creative activities. This dream’s interpretation depends on the context of the oneiric scene, the events that it unfolds, and above all, the sensations and feelings it produces on the dreamer (pleasant or unpleasant).... The Big Dictionary of Dreams
It is an element full of magical connotations. Its malleable character and the form it reacts to heat symbolize transformation processes. The interpretation depends largely on what happens to the wax. It may mean union, passion, curing diseases, willingness to creative activities, or feelings of loss and grief.
The interpretation is significantly influenced by the color. White wax promises marriage and good health; yellow, deception and the possibility of having to attend a funeral; red, the sale of a current asset. To see melted wax is a sign of financial loss and mourning.... The Big Dictionary of Dreams
Sand is part of the land and as such relates to the conscious mind.
The tiny particles that make up sand have an implication of the many thoughts that occupy the mind at any given time. Since sand is so unable to structurally support anything because of its inherent lack of solidity, the symbolic meaning of it relates to the danger of any shifting foundation. How solid is the ground on which you are currently building the structures of your life? Sand is a staple of the beach, where the symbolic consciousness of land meets the symbolic unconsciousness of the ocean. This is the very malleable structure of this ever- changing landscape, and your dream of sand may relate to this.... Complete Dictionary of Dreams
Metals are hard but malleable, a potent symbol of strength and character. Metals can also be cold and, because of their association with technology, represent the inhuman side of our society.... Dream Symbols in The Dream Encyclopedia