Yea hot soapy water should work. I just put mine in the shower for 10-15 mins with warmer water. Are u worried about bugs and pesticides or just dust and dirt?
I would use hot soapy water. If you go online there is ratios on there for killing aphids, I think it's just a few drops of dish soap and the rest water in a spray bottle. Completely drench the plant and don't forget the under side. Let it sit then rinse with regular water. Hope this helps