LiGaO2 and LiAlO2 have similar lattice constants to GaN, and may prove useful as substrates for III-nitride epitaxy. We have found that these materials may be wet chemically etched in some acid solutions, including HF, at rates between 150 and 40,000 Angstrom/min. Dry etching with SF6/Ar plasmas provides faster rates than Cl-2/Ar or CH4/H-2/Ar under electron cyclotron resonance conditions, indicating the fluoride etch products are more volatile that their chloride or metallorganic/hydride counterparts.