Je nettoie le jus renversé sur le sol avec une éponge humide.

Je nettoie is the normal present tense of nettoyer: I clean / I am cleaning.

In French, the simple present often covers both:

• I clean
• I am cleaning

So Je nettoie le jus... can naturally mean I am cleaning the spilled juice... in context.

Je suis nettoie is incorrect because French does not form the present progressive the way English does.

You can say Je suis en train de nettoyer..., but that is more explicit and means I am in the process of cleaning... It is used when you want to stress that the action is happening right now.

Le jus means the juice. It refers to a specific juice spill.

Du jus usually means some juice or juice in a more indefinite sense.

Here, the sentence is talking about a particular mess being cleaned up, so le jus is the natural choice:

• Je nettoie le jus renversé... = I’m cleaning the spilled juice...

If you said du jus, it would sound more like an unspecified quantity of juice rather than a particular spill.

Here, renversé means spilled, knocked over, or overturned, depending on context.

It comes from the verb renverser, which can mean:

• to knock over
• to overturn
• to spill

In le jus renversé, it works like a past participle used as an adjective:

• le jus renversé = the spilled juice

So it describes the state of the juice.

Because renversé agrees with jus, and jus is:

• masculine
• singular

So the correct form is:

• le jus renversé

If the noun were feminine singular, you would use renversée:

• la boisson renversée

If it were masculine plural:

• les verres renversés

If feminine plural:

• les serviettes renversées

In French, most adjectives come after the noun, and that includes many past participles used adjectivally.

So:

• le jus renversé = literally the juice spilled

This is normal French word order.

English often puts spilled before the noun:

• the spilled juice

French usually puts that kind of description after the noun.

Sur le sol means on the floor.

It tells you where the juice was spilled:

• le jus renversé sur le sol = the juice spilled on the floor

Without it, the sentence would still make sense:

• Je nettoie le jus renversé.

But sur le sol gives extra location information.

A very common alternative in everyday French is par terre:

• Je nettoie le jus renversé par terre.

That sounds more conversational, while sur le sol is a bit more neutral or descriptive.

It describes how you clean — specifically, the tool you are using.

• avec une éponge humide = with a damp sponge

So the structure is:

• Je nettoie ... avec une éponge humide
• I clean ... with a damp sponge

It does not normally mean that the floor is damp.
The adjective humide belongs to éponge:

• une éponge humide = a damp sponge

Because in French, most adjectives come after the noun, and humide is one of them.

So:

• une éponge humide = a damp sponge

Putting humide before the noun would sound unnatural here.

Some French adjectives often come before the noun, but humide is normally placed after it.

Une éponge means a sponge, so it introduces the sponge as an indefinite object.

This is natural when the exact sponge is not important:

• avec une éponge humide = with a damp sponge

If you said avec l’éponge humide, that would mean with the damp sponge, referring to a specific sponge already known in the conversation.

So the difference is:

• une éponge = a sponge
• l’éponge = the sponge

French nettoyer can directly take the thing being cleaned up as its object.

So:

• Je nettoie le jus renversé is perfectly natural.

English often prefers clean up in this kind of situation, but French does not need a separate particle like up.

You could also hear:

• J’essuie le jus renversé = I wipe up the spilled juice
• Je nettoie le sol = I clean the floor

So French focuses either on:

1. the substance being cleaned up, or
2. the surface being cleaned

Both are possible depending on what the speaker wants to emphasize.

Yes, it is natural and correct.

That said, a native speaker might also use slightly different versions depending on the situation:

• Je nettoie le jus renversé sur le sol avec une éponge humide.
  Neutral and clear.

• Je nettoie le jus renversé par terre avec une éponge humide.
  More everyday and conversational.

• J’essuie le jus renversé sur le sol avec une éponge humide.
  More specifically I wipe up the spilled juice...

• Je nettoie le sol avec une éponge humide.
  If the focus is more on the floor than on the juice.

So your sentence is good; there are just several natural alternatives depending on emphasis.