Osmium's suggestion (https://www.thevespiary.org/rhodium/Rhodium/chemistry/alhg.osmium.html)
(https://www.thevespiary.org/rhodium/Rhodium/chemistry/alhg.osmium.html), denatured alcohol works well for Al/Hg reductions. For the hell of it, I refluxed some denatured ethanol over CaO (this hadn't been denatured with methanol) and distilled it to compare it with denatured alcohol for reductive aminations, and no discernable difference was observed.