How to pre clean a very dirty LP before Ultrasound Machine?

Hi all,

Just had 750 of my LP's shipped from somewhere where they were stored in less than ideal environment..
A lot of mold, dust and what not...Not a pretty site...

So i ordered an Ultrasonic (V8) machine to start cleaning my collection.
However it seems to me they are WAY too dirty to be put in the Machine as is.

What is the way to give them a pre cleaning? Just rinse with tap water? wipe with a wet lint free optician cloth?

What's the advice?

Thanks!