Is there any way to clean up grease stains on an external surface?

How about vinegar and water, in a pail and use a sponge? Hope the trail isn’t too long.

TSP (Tri Sodium Phosphate) is frequently used to cut through all kinds of crud and grease which has been there for a long time.

When you say exterior surface, are you referring to concrete or to something else?

If concrete, then anything which can be used to get oil stains from a car off the garage floor. If you call someplace like Home Depot, i’m assuming they could recommend something.

@Buttonstc Yes. Painted, rough concrete, and pebbly granite(?) stairs.

Well you sure know how to pick the worst surface, don’t you?
:)
The main problem is that the concrete is SO absorbent.

In addition to whichever degreaser you use, I’d also suggest looking into renting a pressure washer which could flush it out of the recesses and set it to it’s hottest possible setting.

Regardless of where it is, the two most important principles to eliminate grease are hot water and something with enough surfactant action to break up the grease. This applies whether it’s dishes, clothing, or concrete.

I have no idea how much renting a pressure washer would run you, but it may be worth checking with the landlord to see if their maintenance DEPT may have one to loan you. Even if not, at least it shows some effort on your part.

Or you just be stuck with an unhappy landlord. Can he fine you for this? Let us know what happens.

@Buttonstc It’s my HOA, so. Yes.

Try simple green or Dawn dishwashing detergent. Dawn really does break up grease.