Using DNA2 files from master.

code/game/objects/effects/decals/Cleanable/misc.dm

@@ -40,6 +40,14 @@
 	icon = 'icons/effects/effects.dmi'
 	icon_state = "dirt"
 
+/obj/effect/decal/cleanable/attackby(obj/item/weapon/W as obj, mob/user as mob)
+	if(istype(W,/obj/item/weapon/crowbar))
+		var/turf/T = get_turf(src)
+		if(T)
+			T.attackby(W,user)
+			return
+	..()
+
 /obj/effect/decal/cleanable/flour
 	name = "flour"
 	desc = "It's still good. Four second rule!"

code/game/objects/effects/decals/cleanable.dm

@@ -1,7 +1,8 @@
 /obj/effect/decal/cleanable
 	var/list/random_icon_states = list()
+	var/targeted_by = null			// Used so cleanbots can't claim a mess.
 
 /obj/effect/decal/cleanable/New()
 	if (random_icon_states && length(src.random_icon_states) > 0)
 		src.icon_state = pick(src.random_icon_states)
-	..()
+	..()