洗濯 and 掃除: laundry and cleaning
Choose the activity noun according to what is being cleaned.
Doing laundry
洗濯 (せんたく) means washing clothes and similar items. 「シャツを洗濯しました」 means washing a shirt.
「洗濯は終わりましたが、まだ乾いていません」 says washing is finished but the items are not yet dry. Separate washing completion from drying completion.
Cleaning a place
掃除 (そうじ) means cleaning a space or object. 「部屋を掃除しました」 says the room was cleaned.
「掃除の前に窓を開けます」 places opening the window before cleaning, not afterward.
Combining actions with targets
「洗濯機を掃除しました」 means cleaning the washing machine. It does not say clothes inside it were washed.
「今日は掃除だけして、洗濯はしません」 says only cleaning, not laundry, will be done today. Keep the two activities' outcomes separate.
What was cleaned in 「洗濯機を掃除しました」?
Show the answer and why
The washing machine itself. The sentence does not report completed laundry.