Efficient management of faeces and sludge is essential for sustainable sanitation practices. In sanitation systems, proper waste dispersal and management are critical to prevent environmental pollution, particularly surface and groundwater contamination, which can arise from inadequate or poorly maintained systems. Looking to global demand for energy and dwindling fossil fuel reserves, alternative energy sources are becoming increasingly important. Poor faecal waste management directly impacts human health, necessitating resource recovery methods over primary treatment alone. Anaerobic digestion of faecal sludge is highlighted as an environmentally friendly and promising method to produce biogas, addressing the world’s growing energy needs. The fresh faecal matter in this study exhibited significant characteristics, including a chemical oxygen demand of 1820 mg/L, total phosphate of 26.5 mg/L, total nitrogen of 67.6 mg/L, and total carbon content of 23.68 mg/L. The study emphasizes the importance of the carbon-rich co-digestion substrate for enhancing biogas production, with lignocellulose agricultural residues like sorghum identified as an ideal source due to their disposability, renewability, and biodegradability. Through a pyrolytic process, sorghum-derived biochar was produced and found to interact synergistically with faecal sludge, enhancing waste degradation and biogas production due to its favourable C:N ratio. Water displacement measurements over a 10-day period during co-digestion experiments showed a consistent increase in biogas production, underscoring the positive correlation between biochar addition, biogas generation, and organic waste breakdown. This study proposes sustainable strategies for managing faecal sludge and suggests future directions for decentralized waste-to-energy systems. It also advocates for further research into biochar co-digestion applications to support international efforts in resource recovery and sustainable sanitation practices.