OMS take too long too evaporate and does not cut grease the way acetone does. I greatly prefer acetone if I need to soak or wipe down a part for degreasing. YMMV.
While acetone isn't the safest product around, it is safely used all over the country in nail salons - it is frequently the main (and sometimes sole) ingredient in nail polish remover. That said, if I'm working with acetone or any solvent, I wear a respirator. Killed too many brain cells with lacquer once and vowed not to do that again.
The bad thing about acetone is that it may harm certain plastics (but not all). But, the same can be said for other solvents such as brake cleaner.
If you're considering alcohol, denatured alcohol is available by the gallon in the paint supplies aisle near the acetone. It'll be much cheaper than isopropanol from the drug store.
Lacquer thinner, MEK, ethanol, isopropanol, acetone, OMS, gasoline, brake cleaner, kerosene, diesel... all of these have varying degrees of solvent strength and may or may not leave a film. Some are very unhealthy to work with (MEK) and some are explosive (gasoline). Know the product you are working with and take the proper safety precautions. Eye, ear, and lung protection are must with most of them.