Tourist Visa required (Australian passport holder)

I am in a unique/difficult position. I am currently an Australian passport holder currently in United States under ESTA Visa waiver program. I will be here until my trip to China in 1st week of October.

I double checked with Chinese consulates in US and it seems without working permit/status I can't apply locally. I am very worried given timelines of having to mail my application back to Australia and ask a family member to try and apply from country, especially as my flights leave from United States.

The only option I can think of is applying for it in Hong Kong before entering China. Now would this be the best option? How many days should I plan for being in HK before they will be able to issue it?

Any information and guidance you can provide will be appreciated.

Many thanks