CoffeeBox usefully separates loose retained grounds from the oily residue that can accumulate inside a grinder. Both can affect the next dose, especially when moving between very different coffees. An off flavor can have other causes too, so cleaning should be part of troubleshooting rather than the only explanation.
Switch off and disconnect an electric grinder before approved maintenance. Remove only the parts the manufacturer says are user-serviceable, then use an appropriate dry brush or other permitted method for accessible grounds. Do not put water into a motor housing or assume that every burr and internal part is washable. Some removable components have different care requirements.
A grinder-cleaning product is suitable only if the model permits it; household rice is not a universal substitute. Record any setting or alignment instructions needed for reassembly, and ensure all permitted washed parts are completely dry before returning them. The right cleaning interval depends on use and coffee, not one mandatory monthly rule. If the grinder jams, changes sound or requires deeper disassembly, follow service guidance instead of forcing the mechanism or bypassing protective parts.
The conversation
A good question can make a better brew.