A few questions about refinishing a dash

• The previous owner was a heavy smoker and the stains are hard to remove from the unpainted surfaces. I’ve tried alcohol; water based cleaner; and paint thinner - they all work but it’s a very slow process. Any recommendations for a fast working cleaner? I haven’t tried a solvent based wax, grease, and silicone remover
• What is the best method to repair the heat damage?
• What is the best glue to repair the stress cracks?