91% alcohol in a spritz bottle works well and it's enormously cheap. You get a quart of it at drugstores for like a dollar. Use it on metal surfaces only though, it can mess with plastics and rubbers. It's also good mixed with sea-foam for the famous "sea-foam shooters" haha
Honestly I've never found commercial foamy degreasers to work that well. They're too expensive and the can is empty after like 5 seconds of spray.
Still, oil "stains" like that can be tough to get rid of no matter what you use. If you're looking for oil leaks, buy a can of that white foot powder spray. Spray the suspect area and you'll get a nice white coating. Any fresh oil will be very obvious, and then it just wipes off.