Shower related bug fixes (#20018)

![Doom_cover_art](https://github.com/user-attachments/assets/216f8485-a8dc-490b-a526-f1acbfe7d8f6)


Fixed monkey cubes under showers from turning the game into Doom 3.
Fixed showers not showering you because of an improper early return on
wet floors.
Fixed blood overlays being wrongly cleared when you shower.
Sonme code improvements.

code/game/objects/effects/chem/water.dm

@@ -22,7 +22,7 @@
 		var/turf/T = get_turf(src)
 		if(T && reagents)
 
-			if (wet_things(T))
+			if(!wet_things(T))
 				break
 
 			if(T == get_turf(target))
@@ -37,31 +37,34 @@
 
 //Wets everything in the tile
 //A return value of 1 means that the wetting should stop. Either the water ran out or some error ocurred
+/**
+ * Wets everything in the tile
+ *
+ * Returns `FALSE` if the water ran out or some error ocurred, or we should stop in general
+ */
 /obj/effect/effect/water/proc/wet_things(var/turf/T)
+	SHOULD_NOT_SLEEP(TRUE)
 
 	if (!reagents || reagents.total_volume <= 0)
-		return 1
+		return FALSE
 
 
 	reagents.touch_turf(T)
 	var/list/mobshere = list()
-	for (var/mob/living/L in T)
-		mobshere.Add(L)
+	for(var/atom/atom_in_turf as anything in T)
+		if(isliving(atom_in_turf))
+			mobshere.Add(atom_in_turf)
+		else if(!ismob(atom_in_turf))
+			reagents.touch(atom_in_turf)
 
-
-	for (var/atom/B in T)
-		if (!ismob(B))
-			reagents.touch(B)
-
-	if (mobshere.len)
-		var/portion = 1 / mobshere.len
+	if(length(mobshere))
+		var/portion = 1 / length(mobshere)
 		var/total = reagents.total_volume
-		for (var/mob/living/L in mobshere)
-			reagents.splash(L, total * portion)
-		return 1
-
-	return 0
+		for(var/mob/living/mobsphere_living_mob as anything in mobshere)
+			reagents.splash(mobsphere_living_mob, total * portion)
+		return FALSE
 
+	return TRUE
 
 
 /obj/effect/effect/water/Move(turf/newloc)

code/game/objects/items.dm

@@ -853,7 +853,7 @@ var/list/global/slot_flags_enumeration = list(
 /obj/item/clean_blood()
 	. = ..()
 	if(blood_overlay)
-		CutOverlays(blood_overlay, TRUE)
+		CutOverlays(blood_overlay, ATOM_ICON_CACHE_ALL)
 	if(istype(src, /obj/item/clothing/gloves))
 		var/obj/item/clothing/gloves/G = src
 		G.transfer_blood = 0

code/game/objects/structures/watercloset.dm

@@ -224,6 +224,9 @@
 /obj/machinery/shower/proc/on_entered(datum/source, atom/movable/arrived, atom/old_loc, list/atom/old_locs)
 	SIGNAL_HANDLER
 
+	if(QDELETED(arrived))
+		return
+
 	INVOKE_ASYNC(src, PROC_REF(wash), arrived)
 	if(ismob(arrived))
 		mobpresent += 1
@@ -232,6 +235,9 @@
 /obj/machinery/shower/proc/on_exit(atom/movable/gone, direction)
 	SIGNAL_HANDLER
 
+	if(QDELETED(gone))
+		return
+
 	if(ismob(gone))
 		mobpresent -= 1