Reduces the copypaste in cleanable decal code (#20491)

* Only holy water will clean blood runes

* macro!

* holy no longer required

* i am far too unethical and spite driven half the time

* it appears code done in the middle of the night in the hope that oranges hasn't merged my pr isn't always that good

code/modules/mob/living/silicon/robot/robot.dm

@@ -785,9 +785,8 @@
 			if(isturf(tile))
 				tile.clean_blood()
 				for(var/A in tile)
-					if(istype(A, /obj/effect))
-						if(is_cleanable(A))
-							qdel(A)
+					if(is_cleanable(A))
+						qdel(A)
 					else if(istype(A, /obj/item))
 						var/obj/item/cleaned_item = A
 						cleaned_item.clean_blood()

code/modules/mob/living/simple_animal/friendly/cockroach.dm

@@ -53,4 +53,3 @@
 	icon = 'icons/effects/blood.dmi'
 	icon_state = "xfloor1"
 	random_icon_states = list("xfloor1", "xfloor2", "xfloor3", "xfloor4", "xfloor5", "xfloor6", "xfloor7")
-	layer = ABOVE_OPEN_TURF_LAYER