Well, 2 of the 3 Otos I added to my 5 gallon are fat and happy and doing well, they've cleaned all my crypts of any algae and cleaned the glass quite well, and they eat algae wafers! I've been putting in ~1/4 of the small (about dime sized) wafers, and they eat them! The wafers disappear and I've seen the otos picking at them, so i assume it's the Otos not the Betta eating the wafers
The third Oto is AWOL. I couldn't scare him out of hiding when doing a PWC yesterday, but i didn't find a body either. So he may or may not be hiding somewhere, but my hopes are not high, he was the smallest by a good deal. But i'm so glad the other 2 are doing well, i've tried otos before without much luck, so thank you everyone who gave me advice! I think it really helped! :-D