Here are several natural ways to translate “不用洗衣机” into English, depending on the context:

1. Most Common & Literal:

Do not use washing machine.

Do not machine wash. (This is very specific and standard for care labels).

2. For Clothing Care Labels (Most Precise):

Hand wash only. (This implies not using the machine and is the standard phrase on labels).

Do not machine wash. (Explicit instruction).

Machine wash: prohibited. (Formal label terminology).

(Often accompanied by the symbol: a tub of water with a hand, or a crossed-out washing machine symbol).

3. Describing Action/Practice:

Without using a washing machine. (e.g., “I wash my clothes without using a washing machine.”)

Not using a washing machine. (e.g., “The advantage of not using a washing machine is saving electricity.”)

Skip the washing machine. (More casual, e.g., “For delicate items, skip the washing machine.”)

4. Emphasizing Hand Washing:

Wash by hand.

Hand wash.

Which one to choose?

For clothing care instructions: Hand wash only or Do not machine wash are by far the most common and correct translations. Use these.

For general statements about not using a machine: Without using a washing machine or Not using a washing machine are good.

For a direct instruction/command: Do not use (the) washing machine or Do not machine wash.

In summary, the best translations are usually:

Do not machine wash. (For care labels/instructions)

Hand wash only. (For care labels/instructions

Without using a washing machine. (For general description)