I've only been keeping fish for ~6 months or so, not counting our lone betta in a 2.5gallon tank, who required very little effort to keep very healthy and happy, and I've put ottos into our 10 gallon tank before it was fully cycled (I didn't know) and they did perfectly fine, and are still healthy and happy. I recently finished cycling our 36 gallon and added 3 ottos there, and again, they're perfectly happy and healthy.
In my limited experience, if yours come from good stock, and you follow the general necessities of fish-keeping, they should be fine. Mine love finding a piece of sinking algae wafer that the cories miss, enjoy hanging out on the driftwood, and our glass always looks clean (on the inside at least). As long as you don't have agressive fish in there already or anything that might see the otto as food, and as long as your tank is cycled and healthy, I'd give it a try with a few otto.