Practically, you will never receive a 100% finalized reaction in the solutions that involve Ag, Au, or PM. Maybe in very clean and accurate academic cases. Traces of source components are always observable.
The rate of a chemical reaction is highly nonlinear, and a person’s expectations of the result are linear in time, so usually there is not enough patience to wait for a 100% reaction. The first 95% of the reaction will take place, for example, in 24 hours, and the remaining 5% will take another two weeks. This is approximately the proportion of non-linearity.