  Optical clocks represent the most precise experimental devices, finding
application in fields spanning from frequency metrology to fundamental physics.
Recently, the first highly charged ions (HCI) based optical clock was
demonstrated using Ar$^{13+}$, opening up a plethora of novel systems with
advantageous atomic properties for high accuracy clocks. While numerous
candidate systems have been explored theoretically, the considerable
uncertainty of the clock transition frequency for most species poses
experimental challenges. Here, we close this gap by exploring quantum
logic-inspired experimental search techniques for sub-Hertz clock transitions
in HCI confined to a linear Paul trap. These techniques encompass Rabi
excitation, an optical dipole force (ODF) approach, and linear continuous
sweeping (LCS) and their applicability for different types of HCI. Through our
investigation, we provide tools to pave the way for the development of
exceptionally precise HCI-based optical clocks.
