In this work we study cost-effective cleaning solutions applied to interdigitated back-contacted solar cells (IBC), which are passivated by means of atomic layer deposited Al2O3 films. The cleaning baths must guarantee very clean surfaces as well as relatively low etching Al2O3 rates to avoid excessive undercutting at the edges of strip-like regions. We compare the standard high-cost cleaning procedure used in the microelectronic industry (RCA1/2) with simpler cleaning baths based on H2O/NH3/H2O2 mixtures considering different temperatures. The best option is the RCA1/2 sequence yielding surface recombination velocities below 4 cm/s but with a total Al2O3 etch around 500 nm after the cleaning stage. Nevertheless very simple and less aggressive cleaning baths performed at only 45 °C obtain a relatively good surface passivation quality, achieving Seff values of 20 ± 5 cm/s reducing the under etch to only 80 nm.