A great little plugin

Media File Cleaner does exactly what It says it will. Any web developer worth their salt should install the free version first, check out the features then upgrade to Pro. The Pro version at $15 per year is well worth it, there are no limitations on how many sites you can install it on and it ensures the developer is able to spend his time and resources providing us with a product that is regularly updated and well supported whilst still being able to put food on the table. If you don’t want to pay such a small price then go find a free version (if you can) and stop your whining. However be warned as with a lot of free plugins they have a short shelf life, their development is often abandoned early on and are poorly supported. As with most things you get what you pay for.