Following a chemical weapons attack, it is crucial for public health that the toxic chemical agent is properly cleaned up. One particular issue is when the agent has contaminated porous materials, such as brick or concrete. In such cases, decontamination is typically achieved by neutralising the agent with a cleanser in a chemical reaction. It is relatively straightforward to write down a model that describes the interplay of the agent and cleanser fluids on the scale of the pores, but very computationally expensive to solve such a model over realistic spill sizes. In this talk I will present homogenised PDE models for the reactive decontamination of porous media, which are computationally efficient to simulate while still taking the pore-scale behaviour into account. Solutions of these homogenised models show how differences in the initial distribution of agent within the pore-space affect both the decontamination time and the amount of cleanser required to fully decontaminate the porous material.