Privacy is an important aspect of network communications, but privacy protocols require an investment of network resources. For any such protocol to be of use, we need to understand quantitatively how much privacy to expect, as well as the tradeoff between privacy and other network properties, for any given configuration of networks and parameters. We develop a practical privacy measure and protocol model for multichannel secret sharing protocols which integrates privacy and measurable network properties, deriving optimality results for the overall privacy and performance of these protocols. After proving these results, we evaluate the effectiveness of our model by providing a reference implementation and comparing its behavior to the optimality results derived from the model. In our benchmarks, the behavior of this proof-of-concept protocol matched that which is predicted by our model, furthermore, our results demonstrate the feasibility of implementing secret sharing protocols which transmit at a rate within 3-4% of optimal. This model and its results allow us to understand quantitatively the tradeoffs between privacy and network performance in secret-sharing based protocols.