Respecting the dosing recommendations on the package normally no lime deposits should occur.
But to clean the inside of the washing machine of any mold, bacteria, encrusted detergent, and unspecified dirt more effectively than with a normal wash you can run a maintenance wash - without laundry at a high temperature (up 60 °C) from time to time. Use KLAR EcoSensitive BIO Entkalker (deliming powder) or citric acid powder. Put 8 table spoons of Entkalker or citric acid into the machine drum, let run a washing cycle.
Sometimes when washing machines did not run for a longer time, e. g. during holidays, bacteria and mold can develop in the dark and damp corners of the inner machine. Then bad smells can occur.
To avoid bacteria growth you can run a very hot (95°C/203°F) washing cycle monthly.
If smell has established, use Bleaching agent ot get rid of it:put 4 table spoons of the agent into the machine, let run a hot washing cycle (95°C/203°F), without prewashing and without laundry. The oxygen bleaching agent together with the high temperature desinfects the inner of the machine.