Aspects of the disclosure are directed to methods and/or apparatuses involving an apparatus having a channel, an actuator, a mechanical stop, and a dial having nozzles and a gear. The dial is operable to rotate for selectively aligning each of the respective nozzles with the channel. The gear has a plurality of cogs and recessed regions between adjacent ones of the cogs, and is configured with the mechanical stop to prevent movement of the actuator when the dial is positioned such that none of the nozzles are aligned with the channel.